THE OPEN COURT PUBLISHING CO., CHICAGO. 



Biology, Evolution, Etc. Continued 



The Primary Factors of 

 Organic Evolution 



By E. D. COPE. 121 illustrations. Pp. 550. 

 Tables, bibliography and index. Cloth, net, 



$2.00. (lOS.). 



A comprehensive handbook of the Neo-Lamarck- 

 ian theory of Evolution, drawing its main evidence 

 from paleontology, as distinguished from cecology 

 (Darwin) and embryology (Weismann). Discusses 

 the "Energy of Evolution," and lays special em- 

 phasis on the function of consciousness in organic 

 development. 



"Will stand as the most concise and complete exposition of the doc- 

 trines of the Neo-Lamarckian school hitherto published. A most 

 valuable text-book for teachers and students/ ' Science, N Y. 

 "A work of unusual originality. No one can read the book without 

 admiring the intimate knowledge of facts and the great power of 

 generalization which it discloses." Prof. J. McK.Cattell. 



On Germinal Selection 



E. D. COPE. 1840-1897. 



"One of the Great Men of Science of the World. 

 Science, New York, Sept., 1896. 



As a Source of Definitely Directed Variation. 

 By AUGUST WEISMANN. Translated by THOMAS J. 

 McCoRMACK. Pp., xii, 61. Paper, 25c. (is. 6d.). 



"Professor Weismann considers this one of the most important of all his contributions on the evolution problem. . . . . 

 important as marking some fundamental changes in Weismann's position.' Science, New York. 

 "Forms the crown and capsheaf of Weismann's theory of heredity." Exchange. 



On Orthogenesis (Definite Evolution) 



Or the Impotence of Darwinian Selection in the Forma- 

 tion of Species. By TH. EIMER, Professor of Zoology in 

 the University of Tuebingen. Translated by THOMAS J. 

 MCCORMACK. 19 cuts. Pp., 56. Paper 25c. (is. 6d.). 

 This little brochure was written in reply to Weismann's "Germinal Selection." 

 Prof. Eimer argues upon the same lines as the American Neo-Lamarckians, 

 Cope, Hyatt, etc. His doctrine of orthogenesis, which he declares to be a 

 universally valid law, has been framed to show that organisms develop in 

 definite directions, without regard for utility, through purely physiological 

 causes, through the transmission of acquired characters, through the combined 

 agency of the constitution of the animal and the effects of outward influences. 



A Mechanico-Physiological Theory 

 of Organic Evolution 



Summary. By CARL VON NAEGELI. Translated by V. A. 



CLARK and F. A. WAUGH, of the University of Vermont. 



The only original account of Naegeli's theories in English. 



Pp., 52. Price, paper, 15 cents. (gd.) 



Naegeli was the first to propose the general theory of cell-formation accepted 

 to-day. The present little brochure, which is a synopsis of his great work on 

 evolution, will render his difficult theories accessible to English-speaking stu- 

 dents, to whom they have hitherto been almost a sealed book. 



Butterfly's Wing from Eimer's 



ORTHOGENESIS. 



Illustrating the Definite Character of 

 Evolution. 



