[[p. 286]] Leisure-Time Studies; chiefly Biological; a Series of Essays and Lectures. By Andrew Wilson, Ph.D., F.R.P.S.E., &c. With numerous Illustrations. (London: Chatto and Windus, 1879.)

     This volume of Essays and Addresses does not profess to contain anything new, either in the way of observation or theory. Neither is the author's style sufficiently brilliant, or his treatment of the subjects sufficiently original to raise them much above the level of the average lectures of a well-informed naturalist. They will, however, afford some useful and interesting information to the general reader, and may serve to attract attention to the question of the introduction of biology into ordinary education. This is the special subject of the first address, which, however, though somewhat lengthy and profuse, does not attempt to grapple with the difficulty of finding competent teachers of biology for all our schools. It is indeed suggested, that "the amount of knowledge required to pass even the primary stage of the biological subjects, in the government examinations, held under the auspices of the Science and Art Department," should fit its possessor for imparting elementary instruction in biology. But we greatly doubt whether the examiners would be of this opinion; and we rather think it would be a distressing sight to witness a teacher, whose whole knowledge of the subject was derived from a course of study just sufficient to enable him to pass such an examination, exposed to the questions of a lot of intelligent country boys and girls, whose practical acquaintance with native plants and animals was far more extensive and accurate than his own. If biology is to be taught in schools it must not be by the regular school-teachers qualifying themselves by a few months' training in London, but by the employment of good naturalists to give lectures, demonstrations, and out-door excursions to all the schools of a district in succession.

     In the succeeding address, on "Science-culture for the Masses," too much stress is laid on the teaching of science as "a pleasant system of mental gymnastics." This seems to us altogether a wrong ground to go upon. Science is not to be taught in order to strengthen the mind to do something else by and by, but because it opens the mind to a more adequate conception of the universe in which we live, and is in itself, truly, the knowledge which is power.

     The lecture on "The Sea-serpents of Science" is interesting, both as giving a very fair summary of the most recent evidence on this subject, and as showing that the age of incredulity is past, and that naturalists are now prepared to admit that several distinct kinds of oceanic monsters probably exist, of which no single specimen has yet been obtained. Recollecting, however, the number of clever hoaxes to which this subject has given rise, we think that the newspaper account at p. 104, of the declaration before a Liverpool J.P., made by the master and crew of a merchant-ship, to the effect that they had seen a huge serpent twice coiled round a sperm whale, and a similar serpent with its head raised "sixty feet perpendicularly in the air," should not have been inserted as evidence without first ascertaining that such a declaration was actually made before the magistrate named. The trouble of writing a single letter would probably have been sufficient, and would have settled the preliminary question of whether the whole store, from beginning to end, was not a pure newspaper canard.

     The article on "The Genesis of Life" repeats the now often-told tale of the fluctuations of opinion as to spontaneous generation, and will be interesting to those who have not read it elsewhere. Dr. Wilson tries his best to be impartial, and to place before his reader the exact position of the question at the present time. He acknowledges that "isolation" and "destruction" are the two great points of all experiments on the subject, and that if [[p. 287]] these are perfect the question can be settled. It is not denied that hermetically sealed flasks give complete isolation, the only question remaining being, to secure complete destruction of whatever organisms, with their germs, may be within the flasks at the commencement of the experiment. He refers to Dr. Bastian's experiments on the death-point of minute organisms and their germs, which was invariably found to be 158° F., and he points out no fallacy in these experiments. Yet if they are conclusive, Dr. Bastian's numerous other experiments, confirmed as they are by Dr. Burdon-Sanderson and others, demonstrate the production of living organisms from dead matter. The elaborate experiments of Prof. Tyndall are referred to as giving results directly opposed to those of Dr. Bastian; but it is not sufficiently pointed out,--firstly, that in Dr. Tyndall's experiments "isolation" was not effected in the only perfect manner by hermetical sealing, and that many contradictory results hence ensued;--and secondly, that all the results opposed to those of Dr. Bastian were negative, and could therefore not disprove the latter's positive results. Dr. Bastian in his test experiments did not use "old hay," the germs in which are said to be "indurated," but infusions of turnip and cress, and after these were subjected in sealed flasks to temperatures of 270° F., and to 230° F. for upwards of an hour, they produced living organisms of such varied types as bacteria, torula, protamœbæ, and monads. ("Evolution and Origin of Life," p. 175-180.) As similar organisms and their germs, produced in similar infusions have been proved to be killed by a temperature at least 100° lower than that employed in the above experiment, what we require to settle the question is, not thousands of quite different experiments, whose results one way or the other cannot settle the point at issue, but a repetition of the same experiments by other observers with the object of detecting the fallacy, if any, that lurks in them.

     The only other article we can here refer to, is that on "The Law of Likeness and its Working," which deals with the question of heredity, and Mr. Darwin's theory of Pangenesis. But no notice is taken of Mr. Francis Galton's very important "Theory of Heredity," published in the Journal of the Anthropological Institute, vol. v. p. 329; which, though it may be considered as a mere modification of that of Mr. Darwin, really differs from it in many important points, and affords a more complete and satisfactory explanation of many of the most curious facts; such as the unlikeness of children to their parents, the appearance of diseases and even of mental qualities, in alternate generations, and many others. Every one wishing to comprehend this most difficult yet most interesting subject, should study Mr. Galton's paper as a necessary supplement to the theory of Pangenesis.

     At p. 70 of Dr. Wilson's book, a letter from the Times is quoted, describing the formation of the bees' cell, as due entirely to the pressure of opposing bees in adjacent cells. This is not strictly correct; and Mr. Darwin's observations should have been referred to, showing that the cell-walls are first built very thick, and are gnawed down to the requisite thinness. There is also some obscurity in the suggested explanation of the "apparent movement" of the crocodile's upper jaw, when it opens its mouth. The fact appears to be that the crocodile, opening its mouth when on land, must raise its upper jaw and head (by bending the neck) simple because the lower jaw has not room to move downwards. The movement of the upper jaw is therefore, under these circumstances, real, and not only "apparent" as stated. One of the most interesting chapters is that on "Animals and their Environments," in which an account is given of the curious changes during the growth of flat fishes, and the still more remarkable phenomena which have been recently observed in the metamorphoses of the axolotl, and the alpine salamander.

A. R. W.