ESSAYS UPON HEREDITY 



AND KINDRED BIOLOGICAL PROBLEMS. 



By DR. AUGUST WEISMANN, 



Professor in the University of Freiburg, in Breisgau. 



Vol. I., Second Edition, $2.00. Vol. 11., $1.30. 



" Weismann's attempt to solve an old problem has excited great interest in scien- 

 tific circles, and furnishes a fine example of legitimate scientific speculation." — Prof. 

 G. Macloskie, in The Presbyterian aiid Reformed Review. 



" For some years students of biology have been aware that Dr. August Weis- 

 mann, professor in Freiburg University, has materially contributed to the solution 

 of important biological problems, not so much, indeed, by the discovery of new data 

 as by a more searching analysis and more trustworthy interpretation of facts already 

 known. Now, however, for the first time the outcome of his inquiries is made acces- 

 sible in English to the general reader by an authorized translation issued from the 

 Clarendon Press. That the version correctly reproduces the German original, we 

 have the assurance of Dr. Weismann himself, and that it is made in admirable Eng- 

 lish the reader will at once acknowledge. The essays collected in the volume before 

 us were published at divers times during the years 1881-18S8. They all deal either 

 exegetically or controversially with two fundamental problems; namely, the origin 

 and significance of the phenomenon which we call death, and the limitations of the 

 phenomenon which is termed heredity. We should also premise that the discussion 

 of the latter subject leads him to dissent from one of Darwin's conclusions by deny- 

 ing the transmissibility of acquired characters." — The New York Sun. 



" American students of the more profound biological problems are fortunate in 

 having these important essays in so good an English form. Romanes has recently 

 said of Weismann's works, ' A remarkable series of papers, the effects of which 

 have been to create a new literature of such large and rapidly increasing proportions 

 that, with the single exception of Mr. Darwin's own works, it does not appear that 

 any publications in modern times have given so great a stimulus to speculative sci- 

 ence or succeeded in gaining so influential a following.' The work before us is a 

 series of essays presented at various times and in various forms, but all bearing upon 

 one central thought, — that acquired character cannot be transmitted by heredity. 

 The idea is a startling one, and is wide-reaching in its consequences. If demon- 

 strated, it demolishes Lamarckism at one blow. With it, it destroys the whole theory 

 — a favorite one with American workers — that a species may be directly modified by 

 its environment. It does away with the theory of the disappearance of parts from 

 disuse. It establishes the idea that nothing can be transmitted to posterity but what 

 is congenital in the ancestor. In other words, it reduces the workmg force in devel- 

 opment or evolution of species to natural selection operating upon variations in the 

 germ cell. The importance of these essays is thus clear. The essays are eight in 

 number, — the duration of Life ; on Heredity ; Life and Death ; on the continuity of 

 the Germ Plasm as a foundation of Heredity ; Significance of Sexual Reproduction 

 in the theory of Natural Selection ; the number of Polar Bodies and their Signifi- 

 cance in Heredity ; on the Supposed Botanical Proofs of Transmission of Acquired 

 Characters ; the Supposed Transmission of Mutilations, — are devoted to stating the 

 theory and meeting in detail objections that have been urged against it. Some of the 

 essays are too technical for the general reader; but the first three and the last two 

 are simple, and clearly place the theory, its bearing, and the two factors that must 

 appear in the discussion, before the reader." — Old and Neiu Testament Student. 



MACMILLAN & CO., 



66 FIFTH AVENUE, NEW YORK. 

 I 



