16 



THE BLOOD. 



drawn from the vessels, they adhere together and are usually collected into 

 masses. The plaques quickly undergo change out of the body, becoming 



FIG. 8. Blood-plaques and their derivatives, partly after Bizzozero and Laker (Landois). 

 1, red blood-corpuscles on the flat; 2, from the side; 3, unchanged blood-plaques ; 4, a lymph-corpuscle 

 surrounded with blood-plaques ; 5. blood-plaques variously altered ; 6, a lymph-corpuscle with two 

 masses of fused blood-plaques and threads of fibrin; 7, group of blood-plaques fused or run together; 

 8, a similar small mass of partially dissolved blood-plaques with fibrils of fibrin. 



ovoid, elongated or pointed. They sometimes send out processes which give 

 them a stellate appearance. 



Physiologists have no knowledge of the uses of the blood-plaques. The 

 relations which have been supposed to exist between these bodies and the 

 development of the other corpuscular elements of the blood, the phenomena 

 of coagulation, etc., are as yet indefinite and uncertain. 



COMPOSITION OF THE BLOOD-CORPUSCLES. 



The red corpuscles of the blood contain an organic nitrogenized substance, 

 called globuline, combined with inorganic salts and a coloring matter. 

 The composition of the leucocytes has not been accurately determined, and 

 nothing is known of the composition of the blood-plaques. The inorganic 

 matters contained in the red corpuscles are in a condition of intimate union 

 with the other constituents, and can be separated only by incineration. It 

 may be stated, in general terms, that most, if not all of the various inorganic 

 constituents of the plasma exist also in the corpuscles, which latter are par- 

 ticularly rich in the salts of potassium. Iron exists in the coloring matter of 

 the corpuscles. In addition, the corpuscles contain cholesterine, lecethine, a 

 certain quantity of fatty matter and probably some of the organic saline 

 constituents of the blood. 



Globuline. Eollett, by alternately freezing and thawing blood several 

 times in succession in a platinum vessel, has succeeded in separating the col- 

 oring matter from the red corpuscles. When the blood is afterward warmed 

 and liquefied, the fluid is no longer opaque but is dark and transparent. 

 Microscopical examination then reveals the corpuscles, entirely decolorized 

 and floating in a red, semitransparent serum. Denis extracted the organic 



