414 



SCIENCE. 



[N. S. Vol. I. No. 15. 



between 1879 and the time of his death, 

 and before a number of debating societies 

 and scientific organizations, ending with 

 his presidential addi-ess before the British 

 Association in 1890. These addi-esses are 

 all designed for a somewhat popular audi- 

 ence, and treat of diiferent scientific subjects 

 in a clear, entertaining manner. Among the 

 most interesting of them the lectures that 

 will, perhaps, first commend themselves to 

 the reader are those on Fresh AVater Ani- 

 mals, on Inheritance, on Shapes and Sizes 

 of Animals, and the one upon the Recapitu- 

 late Theory. Professor Marshall possessed 

 in a wonderful degree the power of seizing 

 hold of the salient points of abstract scien- 

 tific subjects and isolating them from the 

 cumbersome mass of details with which they 

 are associated in ordinary scientific discus- 

 sions. The result is that in a few pages 

 the reader obtains a clearer conception of 

 the salient points in a subject like embryol- 

 ogy by reading the last of the essaj^s in this 

 volume than he might obtain from the care- 

 ful perusal of many lengthy books upon the 

 subject. Details, of course, are left out, but 

 the salient and interesting points which em- 

 bryology teaches and attempts to teach are 

 presented with wonderful clearness. The 

 addresses are, in short, popular science of 

 the highest type, and one does not wonder 

 after reading them that Professor Marshall 

 was one of the most popular lecturers in 

 the University Extension courses. 



Every teacher is aware how difficult it is 

 to send a young student to literature that 

 will give him a clear, succinct account of 

 evolution. Scientific discussions of one and 

 another phase of the subject are abundant, 

 but usually they are beyond the compre- 

 hension of the ordinary reader. Manj^ a 

 student having been recommended to read 

 Darwin's Origin of Species reads the book 

 with an utter failure to comprehend Dar- 

 winism. ISTor is this the fault of the student. 

 Even the better class of thinking students 



are so handicapped bj' the abundance of 

 material in that Darwinian classic that the 

 thread of the argument is lost, and they are 

 just as likely to confuse Darwin's views 

 with those of Lamarck as thej' are to under-" 

 stand Darwinism. Few students who are 

 beginning the study of modern biology will 

 have any proper appreciation of Darwinism 

 from the study of the Origin of Species, or, 

 indeed, fi-om the study of most of the scien- 

 tific writings on evolution, unless the es- 

 sential facts are presented to them in some 

 form of introduction. For this reason the 

 series of lectures on the Darwinian theory 

 by Professor Marshall are especially val- 

 uable. These lectures are not encumbered 

 with numerous details, but seize hold of the 

 thread of the Darwinian argument and pre- 

 sent it before the reader in such a way that 

 he cannot fail to understand evolution and 

 Darwinism after having finished such a 

 volume. This series of essays wUl, there- 

 fore, be perhaps the best literature to which 

 a student can be sent at the present time to 

 enable him to understand what evolution 

 was before Darwin, what Darwin added, and 

 what have been the subsequent modifica- 

 tions and criticisms of Darwin's theory. 

 Professor Marshall writes as a partisan and 

 thorough believer in Darwin, and presents 

 his facts in such a way that liis readers 

 cannot fail to recognize the full force of the 

 Darwinian argument. Indeed, he naturally 

 exaggerates the force of many arguments, 

 frequently begs the very question of the 

 issue, and the essays are by no means calcu- 

 lated to be critical discussions. The lectures 

 cannot be considered as a fair presentation 

 of the Darwinian theoiy. The innocent 

 reader will conclude that the argument 

 upon Darwinism is all on one side, that 

 every essential feature of it is abundantly 

 demonstrated and all criticisms are refuted. 

 But, in spite of this fault, which comes 

 naturally from one who is attempting to 

 teach a theory in which he so fully believes. 



