THE BEGINNINGS OF LIFE. 147 



organism derives its origin the germinal spot of the 

 ovum. From this all the other centres are derived, 

 either mediately or immediately, and in directions, 

 numbers, and arrangements, which induce the configu- 

 ration and structure of the being. ... As the 

 entire organism is formed at first, not by simultaneous 

 formation of its parts, but by the successive develop- 

 ment of these from one centre, so the various parts 

 arise each from its own centre, this being the original 

 source of all the centres with which the part is ulti- 

 mately supplied. . . . From this it follows, not 

 only that the entire organism, as has been stated by 

 the authors of the cellular theory, consists of simple or 

 developed cells, each having a peculiar independent 

 vitality, but that there is, in addition, a division of 

 the whole into departments, each containing a certain 

 number of simple or developed cells, all of which hold 

 certain relations to one central or capital cell, around 

 which they are grouped 1 . It would appear that from 

 this central cell all the other cells of its department 

 derive their origin/ And then he adds : c Centres 

 of nutrition are of two kinds those which are peculiar 

 to the textures, and those which belong to the organs. 

 The nutritive centres of the textures are in general 

 permanent. Those of the organs are in most instances 

 peculiar to their embryonic stage, and either disappear 

 ultimately or break up into the various centres of the 



1 This doctrine of ' departments,' doubtless, suggested to Virchow his 

 modification of a similar conception, concerning ' cell territories.' 



L 2 



