38 COMPOSITION OF WHITE CORPUSCLES. [BOOK i. 



as we shall see are very similar to and indeed in many ways 

 closely related to the white corpuscles of the blood), we find that 

 this small solid matter of the corpuscle consists largely of certain 

 proteids, or of substances more or less allied to proteids. Our 

 knowledge of these proteids and other substances is as yet im- 

 perfect, but we are probably justified in making the following 

 statement. 



There is present, in somewhat considerable quantity, a sub- 

 stance of a peculiar nature, which since it is confined to the 

 nuclei of the corpuscles and further seems to be present in all 

 nuclei, has been called nuclein. This nuclein, which though a 

 complex nitrogenous body is different in composition and nature 

 from proteids, is remarkable on the one hand for being a very 

 stable inert body, and on the other for containing a large quantity 

 (acording to some observers nearly 10 p.c.) of phosphorus, whicli 

 appears to enter in a certain way into the structure of the mole- 

 cule, whereas in the case of proteids the phosphorus, which is not 

 always present, is, as it were, attached to the molecule. 



The substance however which is present in the greatest quan- 

 tity is one also at present not thoroughly understood, which 

 though it appears to exist in the cell body apart from the nucleus, 

 arid indeed to form a large part of the solid matter of the cell 

 body, has since it seems to be a compound of nuclein and albumin 

 (or some other proteid) been called nucleo-albumin. It, like 

 nuclein, contains a considerable quantity of phosphorus, by which 

 as well as by other features it is distinguished from the globulins, 

 though in some respects it seems allied to that class of proteids, 

 and to a somewhat similar proteid, myosin, of which we shall have 

 to speak later on as a constituent of muscle. 



Besides these two bodies, the white corpuscles also contain a 

 globulin which, under the name of cell globulin, has been distin- 

 guished from the globulin or paraglobulin of blood, as well as a 

 body or bodies like to or identical with serum albumin. 



Next in importance to the proteids, as constant constituents of 

 the white corpuscles, come certain fats. Among these the most 

 conspicuous is the complex fatty body lecithin. 



In the case of many corpuscles at all events we have evidence 

 of the presence of a member of the large group of carbohydrates, 

 comprising starches and sugar, viz. the starch-like body glycogen, 

 which we shall have to study more fully hereafter. This glycogen 

 may exist in the living corpuscle as glycogen, but it is very apt 

 after the death of the corpuscle to become changed by hydration 

 into some form of sugar, such as maltose or dextrose. 



Lastly, the ash of the white corpuscles is characterised by 

 containing a relatively large quantity of potassium and of phos- 

 phates and by being relatively poor in chlorides and in sodium. 

 But in this respect the corpuscle is merely an example of what 

 seems to be a general rule (to which however there may be 



