264 



SCIEN'CE. 



[Vol. VIII., No. 18& 



of the latter : these are 35,691, and 32,645 milUon 

 marks respectively. Of this amount, our own 

 country, fourth in the race, furnishes about one- 

 tenth ; Great Britain leads with one-fifth ; while 

 France and Germany hold the intermediate posi- 

 tions. By such tables the work supplements and 

 often corrects Mulhall's statistical volumes, and is 

 more satisfactory in so far as Dr. Scherzer is more 

 generous in stating his authority for statistics, 

 which are necessarily more or less a matter of dis- 

 pute. This literary accomplishment is one not yet 

 acquired by Mr. Mulhall. Especially desirable are 

 such references when the statistics of gold and 

 silver are given. Not a little of the confusion of 

 the present discussion concerning the merits of 

 bimetallism is due to the conflicting statistics of 

 gold and silver production ; and all writers on the 

 subject should be careful to state their authority 

 when using such figures as a basis for argument. 

 Here Dr. Scherzer follows Neuman-Spallart and 

 Soetbeer. The work is scholarly and painstaking, 

 and will be of service to all students desirous of 

 new statistical conclusions or verification of others' 

 work. 



CONN'S -EVOLUTION OF TO-DAY. 



This book is defined by the author as " a sum- 

 mary of the theory of evolution as held by scien- 

 tists at the present time, and an account of the 

 progress made by the discussions and investiga- 

 tions of a quarter of a century." The book, how- 

 ever, deals chiefly with the evolution of animals. 

 Inorganic evolution is dismissed with some few 

 words about the nebular hypothesis, and, partly 

 in statement and partly by implication, the author 

 expresses the view that inorganic evolution is 

 scarcely worthy of treatment by scientific meth- 

 ods and by scientific men. In so doing, he ignores 

 the entire field of geology. In a manner equally 

 curt, the subject of vegetal evolution is passed 

 over, and the author begins his theme proper, 

 which is a discussion of the nature of the evidence 

 for and against the doctrines of animal evolution. 

 He nowhere gives a clear and comprehensive 

 definition of evolution, though the introduction 

 is largely devoted to a discussion of the term, and 

 to a denial that evolution is equivalent to Dar- 

 winism. Throughout the book an evolution of 

 animal forms is maintained, but the doctrines 

 taught by Darwin, as understood by the author, 

 are, in general, though rather vaguely, denied. 

 The reader is made to feel, that, in the author's 

 mind, Darwinism is the name of something 

 wicked that good people must disavow ; and. 



Evolution of to-day. By H. W. Conn, Ph.D. New York, 

 Putnam, 1886. 8°. 



while the author reaches the conclusion that evolu 

 tion is probably true, he wishes it to be under- 

 stood that there is no taint of Darwinism in his 

 beliefs. 



The first chapter treats of the mutability of 

 species, in which various facts, arguments, and 

 opinions, pro and con, are briefly set forth, and 

 an attempt made to derive an average therefrom ; 

 as if a mean result of contradictions could be used 

 as a proximate truth, in the same manner that a 

 mean of instrumental observations is used as an 

 approximate determination. The same error, but in 

 a minor degree, lurks in the remaining chapters. 



In the second, third, fourth, and fifth chapters, 

 the author reviews the arguments for evolution 

 derived from the principles of classification, the 

 paleontologic succession of forms, the develop- 

 ment of the embryo, and the geographic dis- 

 tribution of animals. In these four chapters he 

 skilfully and fairly characterizes four lines of in- 

 ductive reasoning by which the specialization of a 

 iQultiplicity of foi'ms is demonstrated, and also, 

 though not quite so clearly, shows how progress 

 towards higher forms results therefrorn. This part 

 of the book, which is the body of the work, has 

 great merit as a popular and fair discussion of the 

 subject of the evolution of animals. It is reasonably 

 devoid of technical terms, while broad facts and 

 general principles are happily stated and explained 

 to the understanding of intelligent readers who 

 are themselves not specialists in zoology. In this 

 respect the book is timely ; and the general 

 reader can gather therefrom a very good concep- 

 tion of the doctrines of animal evolution, and the 

 status of development-opinions among scientific 

 men, and of the new problems connected there- 

 with that are arising through expanding research. 

 The author has made as successful an exposition 

 of this subject as, perhaps, is possible by this 

 method of treatment, which is a characterization 

 of facts and arguments, in lieu of a grand 

 marshalling of the facts themselves, — it being 

 the plan of the author to write for the general 

 public rather than for the smaller body of scien- 

 tific men. 



If the reader of Mr. Conn's book could have a 

 preliminary st.udy of some one order of plants or 

 animals, or of some line of embiyologic develop- 

 ment, or if he could study the origin and struc- 

 ture of some mountain-range, or the geology of 

 some river drainage-system, so as to be able to 

 fully appreciate the multitudinous facts that are 

 gathered into some simple induction by the 

 patient labors of modern scientific research, the 

 general characterizations of the author would 

 have a profound effect. Perhaps no man may 

 have a very cletfr comprehension of what the 



