upon their objectives the amplification present when the image formed by such objective is thrown upon a screen at the recognized normal distance of ten inches (or 254 millimeters) from the object we should then have something definite. The mode which I find most convenient for obtaining this amplification of the objective considered in and by itself is as follows: An image of the lines or divisions of a stage micrometer is caused to fall upon the eye-piece micrometer of the micrometer eye-piece -the collective or field glass of the same having been previously removed. The plane or distance from the stage micrometer at which the eye-piece micrometer should be placed, namely, ten inches, may easily be effected by means of the draw tube. By comparison of the lines of the stage micrometer as thus projected, with those of the eye-piece micrometer the amplification of the objective is readily determined; the eye glass of the eye-piece enlarging both sets of lines equally, and greatly facilitating the reading. In this use of the eye-piece micrometer it is necessary that the exact value of its scale should be known, a point unimportant when otherwise used. The scales upon the micrometers which I use and find in general best adapted to the purpose, are a millimetre divided into 1-100 for the stage micrometer, and a centimetre divided into 1-100 for the ocular or eye-piece micrometer.

With the highest respect and kindliest of feelings towards Mr. Bicknell, who has contributed so largely to the advancement of microscopic science in America, I intended in my original communication, not the bring. ing before the public the superior excellence of Mr. Wales' lenses, for of their merit in this country we are all agreed, but to place on record certain resolutions as attained by exceedingly low amplification. — J. J. HIGGINS, M. D.

THE SIMPLEST FORM OF MICRO-TELESCOPE. At a field meeting of the Albany Institute, held in Hoosic Falls, on the 24th of September, Dr. R. H. Ward of Troy, N. Y., exhibited a simpler form of micro-telescope than has hitherto been proposed. He screws an ordinary 4-inch objective (5-8 inch wide, 2 3-4 inches solar focus) into an adapter (about 2 inches long) below the stage of the "seaside," "clinical," or any other handmicroscope. To this object-glass the compound body, with all its lenses, acts as an erecting eye-piece, as in Tolles' telescope and Curtis' microtelescope. Of course, no one would expect from a 5-8-inch opening the light of a 1-inch opening; but the new arrangement gives a really useful field-telescope without requiring a single addition to the microscopist's apparatus. Solid (single combination) objectives act best as erectors in this case, but the ordinary objectives, from 2-inch to 1-2-inch, answer very well. The same arrangement, by raising the tube considerably, aud perhaps substituting a 1-inch objective for the 4-inch. furnishes an erecting compound microscope which is excellent as a hand-magnifier for field use; and by removing the lens below the stage we have the ordinary field microscope on which the object may be placed in the "clinical compressor," or otherwise.

ANTHROPOLOGY.

THE SIGNIFICANCE OF CRANIAL CHARACTERS IN MAN. - Professor John Cleland has communicated to the Royal Society a paper in which he gives an account of some careful investigations into the cranial measurements of various races, and criticises the various methods of craniometry in use - pointing out what facts of growth and relations of parts the observed measurements really indicate. He observes that if the terms dolichocephalic and brachycephalic are to retain any scientific value as applied to skulls, the "cephalic index" (that is, the breadth in terms of the length which is called one hundred) must not be depended on. Other points of importance, as pointed out by Retzius, must be attended to. According to Dr. Cleland, the relation of the height to length of a skull is of great importance. There is no foundation whatever for the supposition, which is a wide spread one, that the lower races of humanity have the forehead less developed than the more civilized nations; neither is it the case that the forehead slopes more backwards on the floor of the anterior part of the brain-case in them than it does in others. Quarterly Journal of Science.

HEREDITARY GENIUS.

In his late work on "Hereditary Genius," Mr. Francis Galton thus describes his purpose:

"What I profess to prove is this: that if two children are taken, of whom one has a parent exceptionally gifted in a high degree-say as one in four thousand or as one in a million-and the other has not, the former child has enormously a greater chance of turning out to be gifted in a high degree than the other. Also, I argue that, as a new race can be obtained in animals and plants, and can be raised to so great a degree of purity that it will maintain itself, with moderate care, in preventing the more faulty members of the flock from breeding, so a race of gifted men might be obtained, under exactly similar conditions."

AMERICAN ASSOCIATION.

NINETEENTH MEETING OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE, HELD AT TROY, N. Y., AUGUST 17TH-24TH. 1870. [Abstracts of papers continued from the November Number.] Mr. F. W. PUTNAM made a communication "On the young of Orthagoriscus mola." He had been led to his investigations by the statement, made by Messrs. Lütken and Steenstrup, that the young of Orthagoriscus differed greatly from the adult, and that Molacanthus was not a distinct genus, but simply the young state of Orthagoriscus. This statement of the distinguished Copenhagen zoologists led him to believe that they had not seen the young of Orthagoriscus and had been misled by the singular form of Molacanthus in considering that genus as the younger state of

*Efversigt Danske Vidensk. Selsk. Forhandl. 1863. p. 36.

the sunfish. He exhibited drawings of Molacanthus, of the adult form of Orthagoriscus mola and O. oblongus, and of the young of the last two. The drawing of the young of O. oblongus was copied from Harting's work. Harting had figured the specimen in connection with remarks Fig. 135. Fig. 134.

Molacanthus Palassii (1-2 grown, natural size).

Orthagoriscus oblongus (young, natural size).

to the effect that he thought the young of this genus were not so different from the adult in form as supposed by Lütken and Steenstrup.

The drawings of the young of O. mola were from specimens taken in Massachusetts Bay and now in the Peabody Academy of Science, having

Fig. 136.

Orthagoriscus mola (young, natural size).

been received from the Essex Institute in whose collection they had been for many years. These specimens, four in number, were about two inches in length, and while differing from the adult in several particulars were yet so near to the adult form in all their important features that no doubt could be

entertained as to their being the young of O. mola. In these young specimens the eye is proportionally very large, and is placed at the margin of the head, while in the adult it is situated some distance from the margin. In the young the dorsal fin and the upper portion of the caudal

Fig. 137.

are thrown respectively a little backward of the anal fin and the lower part of the caudal. By following out a series of 'drawings, taken from specimens of various sizes, he showed how the growth of these fishes was more rapid in their dorsal and anterior parts than in other portions of the body, and that from the pushing forward of the posterior parts, and the tendency to develop a large head at the expense of the body, which culminated in the formation of the projecting "nose" so characteristic of the old specimens, he was led to the conclusion that the various forms of the short sunfishes were all of one species, and those of the oblong type of another; these two forms probably representing two distinct genera of one species each (perhaps two of the mola type)..

These

In the young 0. mola the caudal fin is composed of eight rays in its upper half and eleven rays in its lower half. rays are elongated filaments, and by their regular increase in length as they approached the centre of the fin the caudal be

came a pointed fin.

Orthagoriscus mola (adult, greatly reduced).

Along the ventral portion of these young fishes is a fleshy ridge, easily detached from the body, and armed with several rows of small spines. The back, for about half the distance in front of the dorsal fin, has a slightly raised fleshy ridge.

Several interesting points were mentioned in connection with the skeleton of the young and the changes which take place in its growth. The neural spines of the 5th to the 15th vertebræ are closely packed together with the interneural spines, and extending backwards support

the dorsal fin, while the hæmal spines of the 10th to 16th vertebræ are in close connection with the expanded interhæmal spines supporting the anal fin. The 16th vertebra gives off large neural and hæmal spines, the former having five interneural spines anchylosed with it as in the adult, while the hæmal spine supports nine interhæmal spines, the lower one of which belongs to the anal fin while the others are of the caudal chain. In the adult only seven interhæmal spines are connected with this hæmal spine. The 17th vertebra in the adult lies in the caudal chain of interspinous bones and, from its being separated from the vertebral column, has been as often considered as an interspinous bone as a vertebra. In the young specimens this vertebra, though separated from the column as in the adult, has in close connection with it two bones above and two below, probably indicating that this vertebra is in reality the consolidation of two vertebral bodies, the 17th and 18th, while two other small (neural and hæmal) bones posterior to this free vertebra indicate that a 19th vertebra existed at an earlier stage. These six neural and hæmal (three each) bones disappear in the adult, and with them the central rays of the caudal fin, and they and the 17th, 18th, and 19th vertebræ are only represented by the free or “floating" 17th vertebra which lies in the chain of interspinous bones of the caudal. This is the only instance of a vertebra existing as distinctly separated from the vertebral column known to the author.

A dissection of the soft parts of the young shows the same arrangement as in the adult; the large liver extending in two lobes and enclosing the stomach and portions of the intestine, and the long intestine with its five or six folds. The arrangement of the bundles of muscles is the same as in the adult.

On comparing these young with Molacanthus an entirely different structure is observed. First, the external form of Molacanthus differs greatly from Orthagoriscus; the body is deeper than long in Molacanthus, while the reverse is the case in Orthagoriscus. There are many largely developed spines on the former, and the skin is thin, silvery and smooth between the spines. In the latter the skin is thick, the anterior portion is protected by small granulations and the rest is covered with fine villous scales; there are five singular naked spaces on each side, three of which have a raised granulated margin, and there is a similar raised space just in front of the dorsal fin. In Orthagoriscus the dorsal and anal are closely connected with the caudal, which, in comparison with the adult, is largely developed in the young, while in Molacanthus no caudal fin can be traced, and the dorsal and anal are separated by a naked space (though all the figures of this fish thus far published represent the dorsal and anal as united by a caudal, the row of small dermal spines at this portion having been mistaken for rays). The skeleton of Molacanthus shows the interspinous bones of the dorsal in connection with the neural spines of the 4th to 17th vertebræ, and those of the anal with the hæmal spines of the 10th to 17th vertebræ. The vertebral column in Molacanthus