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side of the structure with lumps of earth. Certain Warblers , into the nest of the dupe, and after the necessary incuba(Aedon and Thamnobia) for some unascertained reason in- tion by the fond fool of a foster-mother the interloper sucvariably lay a piece of snake's slough in their nests--to cessfully counterfeits the heirs, who perish miserably, repel, it has been suggested, marauding lizards who may victims of his superior strength. . The whole process has thereby fear the neighbourhood of a deadly enemy, The been often watched, but the reflective naturalist will pause clay-built edifices of the Swallow and Martin are known to ask how such a state of things came about, and there is to everybody, and the Nuthatch plasters up the gaping not much to satisfy his enquiry. Certain it is that some mouth of its nest-hole till only a postern large enough for birds whether by mistake or stupidity do not unfrequently entrance and exit, but easy of defence, is left. In South lay their eggs in the nests of others. It is within the knowAmerica we have a family of birds (Furnariidæ) which ledge of many that Pheasants' eggs and Partridges' eggs are construct on the branching roots of the mangrove globular often laid in the same nest, and it is within the knowledge ovens, so to speak, of mud, wherein the eggs are laid and of the writer that Gulls' eggs have been found in the nests the young hatched. The Flamingo erects in the marshes of Eider-Ducks, and vice versa; that a Redstart and a Pied it frequents a mound of earth some two feet in height, Flycatcher will lay their eggs in the same convenient hole with a cavity atop, on which the hen, having oviposited, —the forest being rather deficient in such accommodation; sits astride with dangling legs, and in that remarkable atti- that an Owl and a Duck will resort to the same nest-box, tude is said to perform the duty of incubation. The set up by a scheming woodsman for his own advantage ; and females of the Hornbills, and perhaps of the Hoopoes, that the Starling, which constantly dispossesses the Green submit to incarceration during this interesting period, the Woodpecker, sometimes discovers that the rightful heir of males immuring them by a barrier of mud, leaving only a the domicile has to be brought up by the intruding tenant. small window to admit air and food, which latter is assidu- In all such cases it is not possible to say which species is ously brought to the prisoners.
so constituted as to obtain the mastery, but it is not diffiOccasional But though in a general way the dictates of hereditary cult to conceive that in the course of ages that which was departure instinct are rigidly observed by birds, in many species a driven from its home might thrive through the fostering
remarkable degree of elasticity is exhibited or the rule of of its young by the invader, and thus the abandonment
ant, and where most food is there will the feeders be attention will perhaps be more cheerfully given when we Birds gathered together. This explains, in all likelihood, the think how many naturalists, not merely ornithologists, have breeding associated bands of Ospreys or Fish-Hawks, which in been first directed to the study of the animal kingdom by in socie
North America breed (or used to breed) in large companies the spoils they have won in their early days of birds' nesting. Birds' ties
where sustenance is plentiful, though in the Old World the With some such men the fascination of this boyish pursuit nesting. same species brooks not the society of aught but its mate.
has maintained its full force even in old age-a fact not so Birds there are of eminently social predilections. In much to be wondered at when it is considered that hardly Europe, excepting Sea-fowls—whose congregations are any branch of the practical study of Natural History brings universal and known to all—we have perhaps but the the enquirer so closely in contact with many of its secrets. Heron, the Fieldfare, and the Rook, which habitually flock It is therefore eminently pardonable for the victims of this during the breeding-season ; but in other parts of the devotion to dignify their passion by the learned name of world many birds unite in company at that time, and in “Oology,” and to bespeak for it the claims of a science. none possibly is this habit so strongly developed as in the Yet the present writer-once an ardent follower of the Anis of the Neotropical Region, the Republican Swallow practice of birds'-nesting, and still on occasion warming to of North America, and the Sociable Grosbeak of South its pleasures—must confess to a certain amount of disapAfrica, which last joins nest to nest until the tree is said pointment as to the benefits it was expected to confer on to break down under the accumulated weight of the Systematic Ornithology, though he yields to none in his Its uses common edifice. 1
high estimate of its utility in acquainting the learner with Parasitic In the strongest contrast to these amiable qualities is the most interesting details of bird-life—without a know
the parasitic nature of the Cuckows of the Old World and ledge of which nearly all systematic study is but work the Cow-birds of the New, but this peculiarity of theirs is that may as well be done in a library, a museum, or a disso well known that to dwell upon it would be needless. secting-room, and is incapable of conveying information to Enough to say that the egg of the parasite is introduced the learner concerning the why and the wherefore of such
or such modifications and adaptations of structure. To i There are not many works on nidification, for “ Caliology" or the some--and especially to those who are only anatomists— study of nests has hardly been deemed a distinct branch of the science. A good deal of instructive matter (not altogether free from error) will
this statement may seem preposterous, but it is in truth be found in Rennie's Architecture of Birds (London : 1831), and there
no such thing. What engineer can be said to understand is Mr Wallace's most interesting dissertation, "A Theory of Birds' his business if he knows not the purpose to which the Nests,” originally published in the Journal of Travel and Natural machines he makes are to be applied and is unacquainted History (1868, p. 73), and reprinted in his Contributions to the Theory with their mode of working? We may investigate thoof Natural Selection (London : 1870). Mr Andrew Murray's and the Duke of Argyll's remarks on this essay are contained in the same
roughly the organs of any animal, we may trace from volume of the Journal named (pp. 137 and 276).
the earliest moment in which they become defined, and
watch them as they develop to maturity, we may compre- | who early in the eighteenth century explored, chiefly for
of-Paradise and their allies form the only group
in their having fully appreciated the intimate alliance of know absolutely nothing—though there are important iso-
These last, however, though including some
ing too great an importance to such systematic characters and superimposed markings, more deeply-seated stains, ดี
as can be deduced from the eggs of birds, but it would generally of a paler and often of an altogether different
, would appear to be suffused soon of classification, but combined with the evidence afforded after. The depth of colouring whether original or superby due study of other particularities, whether superficial or vening is obviously dependent in a great measure on the deep-seated, it can scarcely fail in time to conduct us to constitution or bodily condition of the parent. If a bird, an ornithological arrangement as nearly true to Nature as bearing in its oviduct a fully-formed egg, be captured, that. we may expect to achieve.
egy will speedily be laid under any circumstances of inThe first man of science who seems to have given any convenience to which its producer shall be subjected, but special thought to oology, was the celebrated Sir Thomas such an egg is usually deficient in coloration-fright and Browne, of Norwich, who already in 1681, when visited by John Evelyn (from whose diary we learn the fact), had ? That the larger end is protruded first was found on actual experiassigned a place in his cabinet of rarities to a collection of ment hy Mr Bartlett, Superintendent of the Gardens of the Zoological The next we hear of is that Count of Marsigli Society, to be the case commonly, but as an accident the position may
be sometimes reversed, and this will most likely account for the occa
sional deposition of mar ings on the sinaller instead of the larger end 1 A small proportion of carbonate of magnesia and phosphate of as not unfrequently shown in eggs of the Sparrow-hawk (Accipiter lime and magnesia also enters into its composition.
nisus). The head of the chick is always formed at the larger end.
captivity having arrested the natural secretions. In like Oorhodeine, Oocyan, Banded Oocyan, Yellow Ooxanthine,
sequence of ill health, give rise to much and often very bands in the red, the true colour of which he has not yet Effect of curious abnormality. It is commonly believed that the been able to decide, and lastly Lichenoxanthine. It would
older a bird is the more intensely coloured will be its eggs, be out of place here to particularize their chemical propercolour.
and to some extent this belief appears to be true. Certain ties, and it is enough to say that they are closely connected
group secrete so much colouring-matter as they do when older, of colouring-matters, but do not actually agree with them. and season after season the dyes become deeper, but there The first is perhaps the most important of all the seven, is reason to think that when the bird has attained its full because it occurs more or less in the shells of so great a vigour improvement stops, and a few years later the inten- number of eggs that its entire absence is exceptional, and sity of hue begins to decline. It would be well if we had it is of a very permanent character, its general colour being more evidence, however, in support of this opinion, which of a peculiar brown-red. The second and third seem when is chiefly based on a series of eggs of one species—the pure to be of a very fine blue, but the spectrum of the Golden Eagle (Aquila chrysaetus), in the writer's possession, former shows no detached bands, while that of the latter among which are some believed on good grounds to have has a well-marked detached absorbent-band near the red been the produce in the course of about twelve years of end, though the two are closely related since they yield the one and the same female. The amount of colouring-matter same product when oxidized. The fourth and fifth subsecreted and deposited seems notwithstanding to be gene- stances supply a bright yellow or reddish-yellow hue, and
rally a pretty constant quantity_allowance being made for the former is particularly characteristic of eggs of the Varieties individual constitution, but it often happens—especially Emeus (Dromæus), giving rise when mixed with oocyan in the same in birds that lay only two eggs—that nearly all the dye wil to the fine malachite-green which they possess, while the .
be deposited on one of these, leaving the other colourless ; latter has only been met with in those of the Tinamous it seems, however, to be a matter of inconstancy which of (Tinamidce), in which it should be mentioned that oorhothe two is first developed. Thus of two pairs of Golden deine has not been found, or perhaps in those of a CasseEagles' eggs also in the possession of the writer, one speci- wary (Casuarius), and when mixed with oocyan produces a inen of each pair is nearly white while the other is deeply peculiar lead-colour. The sixth substance, as before stated, coloured, and it is known that in one case the white egg has not yet been sufficiently determined, but it would seem was laid first and in the other the coloured one. When birds in combination with others to give them an abnormally lay many mottled, and a fortiori plain, eggs, there is gene- browner tint; and the seventh appears to be identical with rilly less difference in their colouring, and though no two one which occurs in greater or less amount in almost all ein hardly ever be said to be really alike, yet the family classes of plants, but is more especially abundant in and resemblance between them all is obvious to the practised characteristic of lichens and fungi. There is a possibility eye. It would seem however to be a peculiarity with some however of this last being in part if not wholly due to the species--and the Tree-Sparrow (Passer montanus) which growth of minute fungi, though Mr Sorby believes that luys five or six eggs may be taken as a striking example-- some such substance really is a normal constituent of the that one egg should always differ remarkably from the rest shell of eggs having a peculiar brick-red colour. That of the clutch. In addition to what has been said above gentleman is further inclined to think that oorhodeine is as to the deposition of colour in circular spots indicating in some way or other closely related to cruentine, being a pause in the progress of the egg through one part of the probably derived from the red colouring-matter of the blood oviduct, it may be observed that the cessation of motion at by some unknown process of secretion, and likewise that that time is equally shewn by the clearly defined hair-lines there is some chemical relation between the oocyans and or vermiculations seen in many eggs, and in none more
the bile. commonly met with than in those of the Buntings (Ember- The grain of the egg-shell offers characters that deserve Grain of izide). Such markings must not only have been deposited far more consideration than they have received until lately, the shell while the egg was at rest, but it must have remained mo- when the attention of Herr von Nathusius having been tionless until the pigment was completely set, or blurred directed to the subject by some investigations carried on
instead of sharp edges would have been the result.1 -by Dr Landois 3 and Herr Rudolf Blasius, 4 he has brought Nature of The composition of this pigment has long excited much out a series of remarkable papers in which he has arrived pigment.
curiosity, and it has been commonly and rather crudely at the conclusion that a well-defined type of shell-structure ascribed to secretions of the blood or bile, but very recently belongs to certain families of birds, and is easily recognized unexpected light has been shed upon the subject by the under the microscope. In some cases, as in the eggs of researches of Mr Sorby (Proc. Zool. Soc. 1875, p. 351), certain Swans and Geese (Cygnus olor and C. musicus, who, using the method of spectrum-analysis, has now ascer- Anser cinereus and A. segetum) even specific differences are tained the existence of seven well-marked substances in the apparent. The bearing of these researches on classificacolouring-matter of eggs, to the admixture of which in cer- tion generally is of considerable importance and must be tain proportions all their tints are due. These he names taken into account by all future taxonomers.
cannot enter into details, it must suffice to remark that 1 The principal oological works with coloured figures are the follow
the grain of the shell is sometimes so fine that the surface ing:- Thienemann, Fortpflanzungsgeschichte der gesammten Vögel (4to, is glossy, and this is the case with a large number of PiLeipzig: 1845); Lefèvre, Atlas des aufs des oiseaux d'Europe (8vo, carice, where it is also quite colourless and the contents of Paris: 1845); Hewitson, Coloured Illustrations of the Eggs of British their eggs seen through the semi-transparent shell give an Birds (8vo, Ed. 3, London: 1856); Brewer, North American Oology (4to, Washington : 1859); Taczanowski, Oslogia Ptaków Polskich (8vo, Warszawa: 1862); Bädeker, Die Eier der Europäischen Vögel (fol. Leip- 3 Zeitschr. für wissensch. Zoologie, xv. pp. 1-31, zig: 1863); Wolley, Ootheca Wolleyana (8vo, London: 1864)--some of Op. cit. xvii. pp. 480-524. which have never been completed ; but a great number of rare eggs 5 Op. cit. xviii. pp. 19-21, pp. 225-270, xix. Pp. 322–348, xx. pp. are also figured in various journals, as the Proceedings of the Zoologi- | 106-130, xxi. pp. 330-335. A summary of these will be found in cal Society, Naumannia, the Journal für Ornithologie, and The Ibis. Journ. für Ornith. 1871, pp. 241-260, and the subject has been con.
? cf ke, Naumannia, 1858, pp. 393-397, and C. Leconte, Revue tinued in the same periodical for 1872, pp. 321-332, and 1874, pp. ct wasin de Zoologie, 1860, pp. 109-205.
Form of egos.
opalescence of great beauty; but among the Tinamous are taken, remarks :—"The reason of this great disparity is,
have the opportunity of making the needful observations
soon as the first egg is laid,4 and this plan unquestionably having this pyriform shape are mostly those of birds which has its advantages, since the offspring being of different invariably lay four in a nest
, and therein they lie with their ages thereby become less of a burthen on the parents which
The size of eggs is generally but not at all constantly in extremity of danger which one at least of the anxious
ther-beaten feathers to be replaced by an entirely new suit.
It is probably the severest strain to which bird-life is ex-
Hewitson, op. cit. Introd. p. X.
with the same individual bird.
Size of eggs.
of proper or even any food does. Important however as flight for a season, during which time they generally seek
mutus), both sexes of which not only moult after the breedAnnual As a general rule all Birds are subject to an annual ing-season is over into a grey suit, and then again as Joult. Moult, and this as above stated, commonly begins immedi- autumn passes away into their snowy.winter-clothing, but,
ately on the close of the breeding-season, but, as will be divesting themselves of this last in spring, then put on
The same may
(Anthince), belonging to the family Motacillidæ, appears, so It is not intended here to describe the way in which a far as our knowledge goes, to be invariable, though the habits
feather dies and a new one succeeds it, nor need we compare and general appearance of both groups are so much alike--. Necessity the process of moulting with the analogous shedding of the the Alaudidæ moulting but once and the anthinæ, conformof moult. hair in Mammals or of the skin in Reptiles. Enough for our ing to the practice of the normal Motacillidæ (Motacillina),
present purpose to see that such renovation is required in twice a year—the quills, be it understood, excepted. But
, by the
3 One species, Micropterus cinereus, seems never to regain the power
of flight thus lost. Cf. Cunninghain, Proc. Zool. Soc. 1871, p. 262. feathers all at once, and become absolutely incapable of * Macgillivray (Brit. Birds, i. p. 196, London: 1837; and Nat.
Hist. of Deeside, p. 405, London: 1855) thought there were four * This is a valuable paper by Herr Meves, of Stockholm (Efvers. moults in this species, but that seems to be one too many. Herr Meves K. Vet. Akad. Förhandl. 1854, p. 258), of which a German transla- (loc. cit.) and the Abbé Caire (Rev. Zool. 1854, p. 494) independently tion with some additions by the author may be found in Journ. für made the discovery of the Triple Moult, and almost simultaneously Ornith. 1855, pp. 230-238.
announced it. Cf. Gloger, Journ. für Orn. 1856, p. 461. * For the knowledge of this fact the writer is indebted to the vast 5 The fullest list as yet published is that of Herr Meves (ut supra), experience of Mr Bartlett.
but it is not entirely free frem error.