THE DUCTLESS GLANDS. 419 



gations seem to have furnished us with more definite infor- 

 mation. In the first place, the large size which it gradually 

 acquires towards the termination of the digestive process, 

 and the great increase observed about this period in the 

 amount of the finely-granular albuminous plasma within 

 its parenchyma, and the subsequent gradual decrease of 

 this material, seem to indicate that this organ is concerned 

 in elaborating the albuminous or formative materials of 

 food, and for a time storing them up, to be gradually 

 introduced into the blood, according to the demands of the 

 general system. The small amount of fatty matter in such 

 plasma, leads to the inference that the gland has little to 

 do in regard to the preparation of material for the respira- 

 tory process. 



Then again, it seems not improbable that, as Hewson 

 originally suggested, the spleen, and perhaps to some 

 extent the other vascular glands, are, like the lymphatic 

 glands, engaged in the formation of the germs of subse- 

 quent blood-corpuscles. For it seems quite certain, that 

 the blood of the splenic vein contains an unusually large 

 amount of white corpuscles ; and in the disease termed 

 leucocythsemia, in which the pale corpuscles of the blood 

 are remarkably increased in number, there is almost 

 always found an hypertrophied state of the spleen or thy- 

 roid body, or some of the lymphatic glands. Accordingly 

 there seems to be a close analogy in function between the 

 so-called vascular and the lymphatic glands : the former 

 elaborating albuminous principles, and forming the germs 

 of new blood-corpuscles out of alimentary materials ab- 

 sorbed by the blood-vessels ; the latter discharging the 

 like office on nutritive materials taken up by the general 

 absorbent system. In Kolliker's opinion, the development 

 of colourless and also coloured corpuscles of the blood is 

 one of the essential functions of the spleen, into the veins 

 of which the new-formed corpuscles pass, and are thus 

 conveyed into the general current of the circulation. 



