THE BEGINNINGS OF LIFE. 227 



was reached we had to do with mere bits of growing 

 protoplasm, or plastides, differing from one another 

 in no other respect except that of size 1 . But in 

 those corpuscles which exceeded Tr-gVo" ^ ie protoplasm 

 gradually became granular, and they then began to 

 exhibit changes which appear characteristic of age and 

 approaching degeneration 2 . Then, also, the nucleus 

 seemed to be evolved as a growing spherule of homo- 

 geneous matter, without distinct boundary wall and 

 therefore appearing as a mere circular space gradually 

 increasing in size amongst refractive granules, which 

 also grew larger and larger. It is extremely difficult to 

 recognize in its earlier stages and when it is very minute 

 in size : there can be little doubt, however, that it is 

 evolved after the same fashion as the nucleus in many 

 vegetable cells 3 . 



Whether the minutest specks of protoplasm seen 



1 Since the above was written I find that Dr. Hughes Bennett has 

 alluded (Lancet, 1863, v l- n -> P- 37^ an d fig- 61) to the occurrence of 

 bodies of different sizes in the blood of certain Leucocythaemic patients. 

 Our interpretation of the appearances is, however, quite different, since 

 he regards the smaller particles as 'nuclei' which have been liberated 

 from the white corpuscles. 



2 I have again and again noticed the results of an evolution of 

 this kind (though more marked in degree") which appears to take place 

 in white corpuscles, after the death of the individual. In autopsies 

 made 36 or 48 hours after death, I have frequently found on examina- 

 tion of the pia mater that the white corpuscles had assumed a most 

 distinctly cellular appearance each cell containing one or perhaps two 

 well-defined ovoidal nuclei, and a variable number of protein granules. 

 -In these cases the corpuscles have a distinctly vesicular appearance, and 

 the nuclei also seem to be bounded by a distinct wall. 



3 See note, p. 184. 



