226 THE BEGINNINGS OF LIFE. 



granular appearance seemed to become more and more 

 marked as the corpuscles became larger, and the nucleus 

 also became more and more distinct, though only ap- 

 pearing as a space free from granules. The corpuscles 

 which were about ^Vu-" in diameter, as well as all those 

 that were of smaller size, presented none of these charac- 

 ters. They were, in fact, not cells but plastides solid 

 homogeneous bits of protoplasm, exhibiting very slow 



FIG. 1 6. 



Showing the different stages in the development of white blood 

 corpuscles, as seen in blood from a case of Leucocythaemia. All 

 gradational sizes to be seen from a mere homogeneous speck of 

 protoplasm S6 ^ 66 " in diameter up to that of a corpuscle of the 

 ordinary size. Those under 5 ^ m " in diameter are homogeneous 

 bits of protoplasm, showing only a very few granules and no 

 nucleus or distinct bounding wall, x 600. 



amoeboid variations in shape 1 . There was no break 

 whatever in the continuity of the series ; all gradations 

 in size could be and were measured, from the mere 

 plastide particle A 1 " in diameter, up to the fully 

 developed corpuscle ; and until the size above indicated 



1 The amoeboid movements of the white corpuscles, however, are not 

 generally very marked in blood taken from Leucocythaemic patients. 

 They have often seemed to be much less obvious than usual a large 

 number of the corpuscles remaining for a long time more or less 

 spherical. 



