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produced abundance of seed annually ready to fill up all vacancies caused by death, could (metaphorically) laugh at all such enemies, and let them devour as they pleased. Such a plant is our own oak tree, which, though infested by galls of many kinds and devoured by numerous caterpillars, is yet not in the least danger of extinction by them, and therefore has developed no special protection against them.
Again, when in any one year much injury is done by caterpillars, that affords such an increase of food to young birds that the insects are almost all destroyed, and in the following year there are comparatively few, giving the trees time to recuperate and attain to their former vigour; while in the following year the birds have less food and are thus diminished in numbers. This wonderful action and reaction of all living things on each other is beautifully described by Mr. Hudson in the chapter of his “Naturalist in La Plata," entitled “A Wave of Life.”
Early in 1879 I read Grant Allen's book on the Colour Sense” (for the purpose of a review in Nature), and wrote to Spruce asking for some information as to the colours of edible fruits in the South American forests. His reply was, as usual, full of interesting and suggestive facts, and I here
"To reply fully to the queries in your last letter would require me to wade through several volumes of my MSS., but I have put together a few excerpta which may serve your present purpose, if they only reach you in time.
“I fear I cannot adduce much evidence as to the fruits most sought after by birds and monkeys. I have seen birds feed on various fruits, but on scarcely any that were not food for man-or at least for Indian man-although a few of them might be too austere, or too acid, for my taste. If, as Sterne says, 'dogs syllogize with their noses,' so do birds with their beaks, monkeys and Indians with their teeth: insomuch as relates to the choice of food. In my long voyage on the Cassiquiare, Alto Orinoco, and some of their tributary streams, my Indians met with many fruits new to
them, all of which that looked at all promising, they tried their teeth on; and, if the taste suited they ate on without dread of consequences. Drupaceous fruits especially were found almost uniformly wholesome, although the juice of the bark &c. might be acrid or poisonous. It is curious that in the Apocynea-an order notable for its abundant milky, and usually poisonous juice—the fruits are rarely, or very slightly, milky, and the succulent fruits (which are found in about half the species) are almost invariably wholesome. You know the Thevetias, whose large bony triangular endocarps, strung together, form the rattles which the Uanpé Indians tie round their ankles in their dances. The milk of the bark is a deadly poison-Humboldt says a scratch from a thumb-nail anointed with it is almost certain death. At Marabitanas a well-grown tree of T. neriifolia grew near the Commandante's house. It bore flowers and ripe fruits-drupes, with a thin yellowish cuticle, and about as much flesh on them as on an average plum; and I noticed that the Commandante's fowls greedily ate up the fleshy part of any fruit that might chance to fall. Seeing this, I thought I might safely eat of them; so I gathered and ate four. What little taste they had was rather pleasant, and no ill effects followed. I had not then seen (as I saw a few years afterwards) what a quantity of black pepper and tobacco a fowl can swallow with impunity, or I might have thought the experiment rather hazardous.
“Many fruits and seeds are sought by animals of all kinds for the sake of their farinaceous or oleaginous properties. The envelope of these, in any part of the world, is not often gaily coloured, although some pods of Amazonian Leguminosæ are deep red, and the contained seeds are very often painted or mottled. I suppose however it is about the succulent, sweet or acid fruits—the drupes and berriesyou chiefly enquire. The great mass of these are certainly as vividly coloured as any fruits of temperate climes—more so indeed, in many cases, than the flowers that precede them. Call to mind the bright reds and yellows of the Peach-palm, the Mango, the enlarged fleshy pear-like petiole of the
Cashew, &c. &c. Purple or almost black fruits, often with a bloom on them, are found in many genera of Palms; in the delicious little sloe-like fruits called Umiri (species of Humirium); in the Cocúras-exquisite grape-like fruits hanging in dense bunches from little trees of the order Artocarpeæ (Pouruma cecropiæfolia, P. retusa, P. apiculata &c.). Among the smaller Palms (Bactris and Geonoma) some have bright red, others black fruits. Papaws have the fruit yellow in the species of the plain; in the mountain species greenish, although some of the smaller ones have scarlet fruit. Myrtles (the berried species, all of which have innocuous, although not many sapid fruits) have in the great majority of Amazon species, black-purple fruits; in some they are red and often intensely acid; in others yellow, &c.
“Succulent fruits with a russet or grey coat are not numerous on the Amazon. There, as elsewhere, they owe that peculiarity to the cuticle minutely breaking up and withering, yet still more or less firmly persisting. Of this class are the very fine and large fruits called Cumá in the Tupi language, yielded by two Apocyneous trees of the Rio Negro (Couma triphylla and C. dulcis) and one of the Orinoko (C. oblonge). The thickish russet rind contains seeds nestling in copious pulp, which eats rather like the fruit of the Medlar or Service, although far sweeter, whence the Portuguese colonists called the tree Sorveira. The bark abounds in thick, sweet and wholesome! milk, which is excellent glue.
"As the Greengage (whose coat is sometimes partly russetgrey) is the finest among European plums, so is the homelycoloured Cumá among all the fruits of the Rio Negro.
"I think I could count on my fingers (if I exclude the melon-tribe) all the edible green drupes and berries of the Rio Negro. The chief of them are the Alligator-pear and some Custard-apples, although some of the latter have a yellow, some a white, and some a red-purple rind.”
Then among other home and private matters comes the remark equally appropriate now, “What an awful state the country is getting into! War and wasteful expenditure seems to be the key-note of our Government."
The special points of interest in the above letter are its complete confirmation of the views derived from European plants, as to use of the colours of fruits in indicating those which are edible for birds or arboreal mammals, while the few exceptions as regards colour are of those large and very sweet fruits whose attractions are sufficient without the signal of bright colour. Again, the very frequent occurrence of acrid or poisonous juice or milk in the bark and leaves, protecting the young shoots and trees from herbivorous animals, combined with perfectly innocuous and often agreeable fleshy or juicy fruits in order to assist in their dispersal, so clearly implies a selective agency in two opposite directions in the same species, as almost to amount to the required demonstration of the existence of natural selection.
I cannot forbear calling attention to the extremely careful wording and punctuation of these letters, written from a sick couch, and of which I have not altered a word or a comma. The clearness and accuracy with which the information is conveyed fittingly corresponds with the writer's careful observation of every aspect and detail of plant life. Had his health permitted more continuous work for a few years longer, he would probably have given us a volume upon all the chief aspects and relations of the vegetation of the forests and mountains of equatorial America, which would have been of the greatest scientific and popular interest.
MY FRIENDS AND ACQUAINTANCES—DR. PURLAND,
MR. SAMUEL BUTLER, PROFESSOR HAUGHTON
ONE of the most interesting, amusing, and eccentric men I became acquainted with during my residence in London, and with whom I soon became quite intimate, was Dr. T. Purland, a dentist, living in Mortimer Street, Cavendish Square. He was a stout, dark, middle-aged man, with somewhat Jewish features, and of immense energy and vitality-one of those men whose words pour out in a torrent, and who have always something wise or witty to say. He had been a great coincollector, and had many anecdotes to tell of rarities hit upon accidentally. He had an unbounded admiration for Greek coins as works of art, and would dilate upon their beauties as compared with the poor and inartistic works of our day. He was something of an Egyptologist, and had many odds and ends of antiquities, including teeth from mummies and dentists' instruments found in the old tombs and sarcophagi. He was a widower with three growing-up children, and had been obliged to part with all the more valuable parts of his collection to educate them.
He was a very powerful mesmerist, and helped, with Dr. Elliotson and others, in establishing the mesmeric hospital then in existence, and could succeed in sending patients into the mesmeric trance when other operators failed. He was one of the few men at that time who had been up in a balloon (with Green, the celebrated aëronaut, I think), and one evening at our house in St. Mark's Crescent, when Huxley and Tyndall were present, he made some remarks which interested Tyndall, who thereupon asked him many questions as to his sensations, the general appearance of the earth, clouds, etc.,