160 THE FLUIDS. 



The nuclei are single, double, triple, or multiple. They are ren- 

 dered more visible by the action of water, but dilute acetic acid 

 exposes them by dissolving the cell-wall. 



The size of the colorless corpuscles is varied by the endosmotic 

 action of the fluid portion of the blood ; hence the richer the blood 

 is in water, the larger they are, and vice versa (p. 145). 



The cytoid corpuscles of the blood are more abundant in young 

 animals, and after venesection ; and in the blood of pregnant women 

 during the last months of pregnancy. They are also more abun- 

 dant in venous blood. (Kolliker.) An abnormal development of 

 them constitutes leuccemia. Pya3mia, also, is scarcely distinguish- 

 able from the latter, since the pus-corpuscle is not to be distin- 

 guished from that under consideration, as will be shown under the 

 head of "Pus." 



Origin. The colorless blood-corpuscles, like all other cytoid cor- 

 puscles (p. 146), are originally developed, by free cell-development, 

 in the lymph, the chyle, and perhaps also the liquor sanguinis. 

 Secondarily, however, new cells may, doubtless, be developed from 

 pre-existing ones, and thus their multiplication seems actually to 

 occur. Lehmann states that they are, "under certain conditions, 

 doubtless formed in the liver ; but their formation, or, at all events, 

 their development and growth, are not confined to any one definite 

 locality, but proceed in the vessels of very different organs." Kol- 

 liker maintains that the cytoid cor- 

 Fi S- 96 - puscles of the chyle originate in the 



a minutest lacteals. He there found nu- 



clei, either free or surrounded by gran- 

 ules, and very fragile young cells, with 

 ^^ walls almost touching the nucleus, and 



^BB^ _ ^ states that they increase in size on 

 /:<&& foil their way to the thoracic duct. In the 

 latter he found none of these nuclei, 

 but two kinds (larger and smaller) of 

 lymph-granules; and maintains that 

 colorless biood-corpuscies in various the smaller only are converted into 



phases, a, a. Stellate form occasionally , -1-111 i 1-11 



seen after escape of their contents. 6,6. the red blood-COrpUSCleS, while the 



Free nuclei, c. A nucleus surrounded } arger are gradually dissolved in the 



by a few granules. d,e. Small cells, some o o ./ 



with a distinct nucleus. /^.Larger ceiis, blood. The various phases of their 

 one with a visible nucleus, h similar development are shown in Fig. 96. 



cell after addition of water, i. Similar 



cell after addition of acetic acid. Uses. Histologically, the Cy toid COr- 



