178 Recent Literature. | zo?: 



the topic, The Limits of Reversion, the author calls attention to 

 the fact that an abnormal organ or structure, even though it re- 

 sembles some normal structure in a lower animal, is not necessarily 

 a reversion, but may be a coincidence. 



There is danger of forgetting the branching plan of evolution and 

 jumping to the conclusion of a connection where none exists. In 

 concluding, Dr. Osborn says: " There are clearly marked out sev- 

 eral regions in the human body in which evolution is relatively most 

 rapid, such as the lower portion of the chest, the upper cervicals, 

 the shoulder girdle in its relation to the trunk, the lower portion of 

 the arm and hand, the outer portion of the foot. We notice that 

 these regions especially are centers of adaptation to new habits of 

 life, in which new organs and new relations of parts are being ac- 

 quired and old organs abandoned. 



We observe, also, that all parts of the body are not equally 

 variable, but these centers of evolution are also the chief centers of 

 variabilit}'. The variations here are not exclusively, but mainly, of 

 one kind ; they rise from the constant struggle between adaptation 

 and the force of heredity." c.a.k. 



The Bijjicidties in the Heredity TJieory. By Henry Fairfield 

 Osborn.* In the second Cartwright Lecture for 1892, Dr. Osborn 

 discusses the bearing of the facts of human evolution enunciated in 

 his previous lecture upon the inheritance of acquired characters. 

 The generalizations in this paper are, for the most part, re-state- 

 ments of his views upon this subject, in some cases from new points 

 of view. 



The history of the heredity theory is briefly outlined, and the 

 effect of impacts and strains upon the mammalian foot and the 

 wearing of cusps is again alluded to. The article concludes with 

 some brief remarks on the inheritance of mutilations, the effects of 

 previous fertilization, and maternal impressions. The author is in- 

 clined to believe in all three, and especially declares his acceptance 

 of the influence of maternal impressions upon the young. The 

 note upon the inheritance of mutilations of the tails of mice is of 

 interest, but, as the author remarks, would need confirmation. 



C.A.K. 



* The Am. Nat. xxvi, 537-567. 



