10 SCIENCE PROGRESS. 
At this point the writer intercalates another clear state- 
ment of the essential distinction between inherent hereditary 
and acquired non-hereditary characters. The statement is 
so admirable that I quote it in full. 
“We may remark in general that each individual being, 
through the animal and vegetable worlds, has certain laws 
of organization impressed upon its original germ; according 
to which the future development 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 predispositions are derived 
the characteristic differences, and the peculiarities of indi- 
vidual beings. Now it appears that such spontaneous 
tendencies are alone hereditary, and that whatever changes 
of organization are superinduced by external circumstances, 
and are foreign to the character of structure impressed upon 
the original stamina, cease with the individual, and have no 
immtuence 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 development.” 
These sentences might well have been written to-day, 
to sum up the results of all our observations on such 
subjects. These results 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 question 
of disease and discusses predisposition. He points out that 
medical writers have generally believed that any predisposi- 
tion to disease may arise in any constitution if subjected to 
