Charles-Sedgwick Minot 2-i7 



the influence of His clearly, and I cannot let the opportunity pass of 

 expressing publicly my gratitude and admiration for the greatest anat- 

 omist of his time. 



Although embryology has already contributed in so ample measure to 

 the promotion of our science, we are still far from having accepted all the 

 enlightenment which she offers us. With your permission I will try 

 to present to you certain embryological aspects of anatomy, the character 

 of which I have sought to indicate in the title of this address, by the 

 words " genetic interpretations." 



First of all, let us consider the subject of cytomorphosis. This word 

 I proposed in 1901 ^ '"to designate comprehensively all the structural 

 modifications which cells or successive generations of cells may undergo 

 from the earliest undifferentiated stage to their final destruction." As 

 stated on that occasion it is convenient, though somewhat arbitrary, to 

 distinguish four fundamental successive stages of cytomorphosis. These 

 stages are (1) the undifferentiated stage: (3) the stage of progressive 

 differentiation, which itself often comprises many successive stages; (3) 

 the regressive stage or that during which degeneration or necrobiosis 

 occurs; and (4) the stage of the removal of the dead material. The gen- 

 eral data on which the conception of cytomorphosis is based have been 

 briefly put together also in my text-book of embryology, and it seems 

 therefore superfluous to dwell upon them at length in addressing you. 



I cannot of course claim any greater originality in the establishment 

 of the conception of cytomorphosis than is implied by the definite formu- 

 lation of the ideas upon which it is based. These ideas have been 

 gradually gathered as the fruit of numerous investigations in histogenesis. 

 The mentioned investigations have made us all familiar with the con- 

 ception of undifferentiated embryonic cells, with the gradual progress of 

 differentiation in the cells during the emljryonic, foetal, and even post- 

 natal periods; and have also made us acquainted with various examples 

 of degeneration and atrophy occurring in the course of development, both 

 before and after birth. Up to the time when I proposed the term there 

 had been, so far as I know, no attempt to survey all this array of facts 

 from a single unifying point of view. But such a point of view is, I 

 believe, well calculated to render our notions more precise as to many 

 processes of development, and to afford us at the same time the practical 

 benefit of being able to present the facts of histogenesis in our teaching 

 in a wav, which is very advantageous, because it facilitates in the stu- 

 dent's mind the establishment of a real insight into the general course of 

 development by emphasizing principles of very wide application. To me, 

 nt least, it seems that the conception of cytomorphosis should be made the 



