168 



LETTERS OX TREES. 



letter ; but it will be conyenient before entering on 

 the discussion, to put you in possession of both 

 branches of the argument. The former I laid before 

 you in section 6 of my last letter — which section I 

 must beg you will now turn to and carefully read 

 over. The latter is as follows : — 



" There appears, then, to be no medium between, on the one 

 hand, regarding the entire fabric developed from a single genera- 

 tive act (z. e., the fertilisation of a single ' germ-cell' by the con- 

 tents of a ' sperm- cell ') as forming one organism^ however great 

 maybe the multiplication of similar parts, or however indepen- 

 dent these parts may be of each other ; and the inckiding every 

 product of its own development, whether contemporaneous or 

 successive, as one generation; or, on the other hand, attributing 

 a distinct individuality to every component of the most com- 

 plex organism, and designating every augmentation of the 

 number of its cells, by the subdivision of those previously exist- 

 ing, as the production of anew generation."* 



It is but fair to Dr Carpenter to subjoin what he 

 further adds : — 



In either case, it must be freely admitted, we are forced 

 to do a certain violence to our ordinary conceptions." "And 

 it may be the wisest course, perhaps, to invent new terms, 

 rather than to distort the meaning of those in common use." t 



3. Putting together, now, what I have here quoted 

 and what I quoted in my last letter (section 6), and 

 having regard also to certain other relative state- 



* Principles of Physiology, General and Comparative, 3d Edition, 

 p. 904. 



t Ibid, pp. 904, 905. 



