No. I.] BLOOD CORPUSCLES. 3^ 



extruded nucleus in this case again becomes a blood plate and 

 may enter upon a similar course of development. 3. In cases 

 of strong anaemia one finds occasionally that certain of the red 

 corpuscles (the poikilocytes, apparently, of the pathologist) con- 

 strict off small bits of their substance to form small red cor- 

 puscles (microcytes .-') somewhat larger than the blood plates 

 which afterwards develop into normal red corpuscles while in 

 the circulation. Boettcher (37) contends that the red corpuscle 

 of the blood in man and the mammalia generally is nucleated, 

 though the nucleus under ordinary conditions is not visible. 

 His evidence for this belief is not at all conclusive : it seems 

 to rest chiefly upon the fact that reagents which dissolve the 

 haemoglobin out of the corpuscles, especially chloroform, leave 

 behind a colorless sphere, considerably smaller than the orig- 

 inal corpuscle, which he takes to be the nucleus. When the 

 action of chloroform upon a red corpuscle is watched, it can 

 be seen, he says, that the reagent dissolves off the peripheral 

 colored portion of the corpuscle, leaving behind the colorless 

 nucleus. Efforts to bring out this nucleus by the action of 

 ordinary staining reagents failed except in two cases, once from 

 the blood of a person who had died from leukaemia, and once 

 from the blood of a tuberculous woman. It is fair to suppose 

 that in both of these cases he was dealing with nucleated red 

 corpuscles which had passed into the circulation. 



Sappey (38) also asserts that the mammalian red corpuscle is 

 nucleated, and that to bring out the nucleus one must treat 

 the blood with some reagent which will make the corpuscles 

 spherical. He recommends the following liquid : water, 500 

 grms. ; sodium sulphate, 40 grms. Add to this solution acetic 

 acid in the proportion of i to 49. Quite recently, Cuenot (39) 

 has advanced a theory of the development of the red corpus- 

 cles which in some respects is more fanciful than any yet de- 

 scribed. He believes that the red corpuscles are formed in 

 the spleen, and in mammals that the whole development is car- 

 ried on in this organ, while in the lower vertebrates a certain 

 portion of the development takes place in the circulation. The 

 spleen, according to Cuenot, contains two kinds of colorless 

 corpuscles, — some of large size and but little refractive, which 

 are destined to form the white corpuscles ; and some of smaller 

 size, which are very refractive, and become the nuclei of 



