300 THE AMEBIC AX NATURALIST [Vol. LIV 



tional pad throughout life, taking the place of the herecl- 

 • i_ ■:. persists structurally 



(Figs. 6 and 7). The new callosity is continuous laterally 

 with the old median one, and altogether resembles it in 

 character. Xo trace of it however appears in the chick 

 prior to hatching (Fig. 5), hence it represents an indi- 

 vidually acquired, adaptive character in the truest sense. 

 We have therefore an original part of the ankle callosity 

 which is hereditary, though now non-functional, and an 

 acquired part which is functional and non-transmissible. 5 

 The main facts presented seem capable of interpreta- 

 tion only in one of two ways: (a) An ac<grired charact er 

 which represents a structural response to stimuli result- 

 ing from the activities of the organism may become 

 transmissible, (b) A character map arise genniuallg of 

 a form and nature exaetlp similar to one which would 

 otherwise be acquired independently from the known 

 activities of the organism and the established responsive 



