ZOOLOGY 455 



The explanation of natural evolution given by Darwinism and the 

 principles of Weismann, Mendel and De Vries, still fails to solve the 

 mystery completely, and appeal has been made to other agencies, even 

 to teleology and to " unknown " and " unknowable " causes as well as 

 to circumstantial factors. A combination of Lamarckian and Dar- 

 winian factors has been proposed by Lloyd Morgan, Mark Baldwin and 

 Professor Osborn, in the theory of organic selection. The theory 

 of orthogenesis propounded by Naegeli and Eimer, now gaining much 

 ground, holds that evolution takes place in direct lines of progressive 

 modification, and is not the result of apparent chance. Of these and 

 similar theories, all we can say is that if they are true, they are not so 

 well-substantiated as the ones we have reviewed at greater length. 



The task of experimental zoology is to work more extensively and 

 deeply upon inheritance and variation, combining the methods and 

 results of cellular biology, biometrics and experimental breeding. We 

 may safely predict that great advances will be made during the next 

 few years in analyzing the method of evolution ; and that a few decades 

 hence men will look back to the present time as a period of transition 

 like the era of re-awakened interest and renewed investigation that 

 followed the appearance of the " Origin of Species." 



We must now state distinctly and fairly the present views of science 

 regarding man's place in nature. Surely human evolution is a subject 

 that falls within the scope of zoological investigation, unless indeed it 

 can be shown that the human species is exempt from the control of 

 those laws of nature that hold sway over the animate world elsewhere, 

 unless something can be found which excludes man from the animal 

 kingdom. Notwithstanding the most prolonged search not only by 

 zoologists but as well by those who have been unfriendly to the doc- 

 trine of descent, the study of man and of men has revealed nothing 

 essentially unique. What is known of the anatomy, development and 

 fossil relations of man is summarized in the statement that he belongs 

 to the genus and species Homo sapiens, placed with the apes and some 

 other forms in the order primates because of agreement in certain 

 peculiar details. The primates agree with the carnivora, rodents and 

 many other orders in the characteristics of the class mammalia, which 

 in turn is only a branch of the limb vertebrata or chordata, which also 

 bears the avian, reptilian, amphibian and fish branches. And all the 

 vertebrates including man agree with the varied groups of invertebrates 

 in their cellular constitution and in the similar protoplasmic basis of 

 life. As in these structural respects, so in physiological activities and 

 in environmental relations the human species proves more surely with 

 increased knowledge to be only one of the terms in the extensive series 

 of animals. Indeed, the scientific monism of Haeckel and Clifford 



