COLOURLESS BLOOD-CORPUSCLES. 181 



puscles are usually found aggregated in rows, presenting 

 the familiar form of rouleaux of money, with their flat 

 discs one against the other (Fig. 52, d) ; in the interspaces 

 may be observed here and there one of these pale, spheri- 

 cal bodies, in which in the first instance, when the blood is 

 quite fresh, nothing more can be distinguished than an 

 occasionally slightly granular- looking surface. If water 

 be added, the colourless corpuscles are seen to swell up, and 

 in proportion as they absorb the water, a membrane first 

 becomes distinct ; then granular contents gradually come 

 into view with more and more clearness, and at last some 

 indication is perceived of the presence of one or several 

 nuclei. The apparently homogeneous globule is gradu- 

 ally transformed into a structure with delicate walls, and 

 often so fragile, that when water is incautiously added, 

 the external parts begin to fall to pieces, and in the in- 

 terior a somewhat granular mass displays itself, which 

 becomes looser and looser, and discloses within it a nu- 

 cleus generally in process of division, or several nuclei. 

 These may be made to display themselves with much 

 greater rapidity, by treating the object with acetic acid, 

 which renders the membrane translucent, dissolves the 

 nebulous contents, and causes the nucleus to coagulate 

 and shrivel up. The nuclei then are seen to be dark bo- 

 dies with sharply defined outlines, and one or more in 

 number according to circumstances. In short, we ob- 

 tain in this way in the majority of cases the view of an 

 object which presents the peculiar appearance that one 

 of our confreres now present, Dr. Gtiterbock, first pro- 

 claimed to be the special characteristic of pus-corpuscles. 

 The question concerning the resemblance or want of re- 



tion of acetic acid : a c, cells with a single, granular nucleus, which becomes pro- 

 gressively larger, and is finally provided with a nucleolus. d. Simple division of the 

 nuclei, e. A more advanced stage of the division, f h. Gradual division of th 

 nuclei into three parts. i k. Four and more nuclei. 280 diameters. 



