66 HISTOLOG 1 ' OF NUTRIENT PL UIDS. 



lin. It is a crystallizable albuminous substance, and always 

 exists in the body loosely combined with oxygen. On this 

 account it is termed oxy -haemoglobin, to distinguish it from 

 the same substance deprived of oxygen by reducing agents. 

 Oxy-haemoglobin crystallizes sometimes spontaneously, but 

 more or less readily with various reagents, or after putrefaction 

 or freezing. In man and most animals the crystals are prisms 

 or rhombic plates of blood-red color. In the guinea pig they 

 are tetrahedric, and in the squirrel hexagonal. Fig. 5, PI. 3. 

 In old hemorrhagic spots and effusions oxy-haemoglobin is 

 changed into haematoidine, which also yields small rhombic 

 crystals. This substance is considered identical with bilrubin, 

 the coloring matter of the bile. Haematoidine differs from 

 haematine by containing one part less of iron and one more of 

 water. Haematine contains 7 per cent of iron, and as in an aver- 

 age body there are about 100 grammes of haematin, the quantity 

 of iron in the whole mass of blood is about seven or eight 

 grammes. 



It is an interesting chemical fact that the red globules con- 

 tain different salts from those of the plasma. They have 

 principally phosphates and salts of potash, while the fluid con- 

 tains chiefly carbonates and salts of soda. Kuss infers from 

 this that potash salts are more useful than soda when we wish 

 to increase the number of red globules. 



VII. ORIGIN OF THE BLOOD CORPUSCLES. 



We consider the white corpuscles as elementary or embryonic 

 particles of bioplasm produced by rapid multiplication in the 

 lymphatic glands or in proliferating endothelium in the serous 

 cavities. Some histologists think the red globules to be pro- 

 duced by the transformation of the white ones, and Reckling- 

 hausen, Kolliker, etc., describe all the transitional forms. 

 Others contend that they differ so much as to point to a differ- 

 ent origin. Malassez considers the red giotmles the product 

 of invisible nuclei from certain marrow cells, and Hayem 

 claims that they are produced by haematoblasts. 



The lymphatic system, including the spleen, lymphatic 

 glands and red bone marrow, and perhaps, also, the thy m us, 



