24 BLOOD CORPUSCLES. 



C., the first fact that we notice is that the movements of the 

 colorless corpuscles in general, and of the granular ones in 

 particular, are much more active. We shall not, however, oc- 

 cupy ourselves at present with these, but shall direct our atten- 

 tion to the three kinds of corpuscles which we have included 

 in our third division. 



On the warm stage we may observe in these bodies (which 

 differ only in size) two kinds of change. One of these consists 

 of alteration in the form of the protoplasm, from the surface 

 of which processes shoot out in all directions. This is more 

 particularly seen in the forms we have designated b and r. 

 In the form a, although the nucleus at first appears bare, it is 

 afterwards seen to be surrounded by a protoplasmic envelope; 

 this may throw out a pointed process, which, after stretching 

 out to a considerable length, is retracted, to be succeeded by 

 others. If the preparation is kept for a length of time at 38, 

 the elements of the form a undergo other remarkable altera- 

 tions. They become strongly refractive, lose their double 

 contour and sharply-defined aspect, and acquire a form which, 

 at first globular, subsequently exhibits constrictions ; so that 

 they become in succession kidney-shaped, dumb-bell shaped, 

 and rosette-shaped, until thej r eventually assume a nodulated 

 aspect. In the course of the process it is common to observe 

 the furrows or constrictions forming, disappearing, and reap- 

 pearing repeatedly; but, sooner or later, they become more and 

 more distinct and complete, so that the body assumes the ap- 

 pearance of a clump of highly refractive minute globules. Con- 

 sidering the coincidence of the changes of form and aspect of 

 the nucleus with those which occur simultaneously in the cell, 

 it is scarcely possible to doubt the dependence of the former 

 upon the latter, especially if we bear in mind the concomitant 

 changes in optical properties. So that we must regard these 

 appearances as indicating that the nuclei take an active part 

 in the changes of form. 



In the form c the cell-substance itself may be also the seat 

 of a process of division. In one instance at least I have, of 

 course after many hours of observation, witnessed the division 

 of a cell which originally contained five nuclei. The cell in 

 question in the first place exhibited a transverse furrow : this 

 became deeper and deeper, so that, eventually, two masses 

 were formed, united together by a neck, the smaller containing 

 two nuclei, the larger three. These nuclei had already under- 

 gone the process of cleavage above described. By the length- 

 ening, thinning out, and final rupture of the isthmus, the two 

 corpuscles came apart. In the larger of the two, which was 

 now exclusively observed, there appeared gradually two boss- 

 like prominences, each of which contained a number of small 

 bodies resulting from the cleavage of the nuclei. By the con- 



