MODERN VIEWS ON EVOLUTION 183 



through the animal and vegetable worlds, has certain laws 

 of organization impressed upon its original germ ; accord- 

 ing to which the future developement of its structure is 

 destined to take place. These inbred or spontaneous 

 tendencies, governing the future evolution of the bodily 

 fabric, cause it to assume certain qualities of form and 

 texture at different periods of growth. From these pre- 

 dispositions are derived the characteristic differences, and 

 the peculiarities of individual beings. Now it appears 

 that such spontaneous tendencies are alone hereditary, 

 and that whatever changes of organization are superin- 

 duced by external circumstances, and are foreign to the 

 character of structure impressed upon the original stamina, 

 cease with the individual, and have no influence on the 

 race. 



' Yet this law of hereditary conformation exists with 

 a certain latitude or sphere of variety, but whatever 

 varieties are produced in the race, have their beginning 

 in the original structure of some particular ovum or germ, 

 and not in any qualities superinduced by external causes 

 in the progress of its developement.' 



These sentences might well have been written to-day, 

 to sum up the results of all our observations on such 

 subjects. They have been summed up at greater length 

 and in more technical language, but I venture to think 

 that Dr. Prichard's statement contains everything that 

 is valuable and essential in every later attempt. It will 

 be observed that Weismann's conception of inherent 

 characters as blastogenic, acquired as somatogenic, stands 

 out clear and distinct ; furthermore, that the source of 

 individual difference is traced to the germ. 



After these general statements he returns to the ques- 

 tion of disease, and discusses predisposition. He points 

 out that medical writers have generally believed that any 

 predisposition to disease may arise in any constitution if 

 subjected to the appropriate causes ; ' that . . . the gouty 

 diathesis, for example, may be acquired by long habits of 

 intemperance, and transmitted to posterity,' and so also 

 with other ill effects witnessed in the children of dissolute 

 parents. If this be so, Prichard admits that 'we have 



