SECT. 221.] DIFFERENT KINDS OF BLOOD. 523 



not surprising that it has not yet been recognised with certainty. 

 At any rate, I must add my positive testimony to that of Henle, 

 that all those well-marked forms, the jagged blood-corpuscles on 

 the one hand, and the diminished spherical ones, coloured or dis- 

 coloured, on the other hand, are never met with in the circulating 

 blood. It is not, indeed, impossible that slight degrees of flatten- 

 ing and swelling of the blood-corpuscles may hereafter be detected, 

 though it must never be forgotten in such investigations, how 

 quickly the blood-corpuscles alter their forms ; and we must be 

 on our guard against regarding as a natural condition, an appear- 

 ance which has arisen for the first time after the blood has left 

 the circulation. — The numbers of blood-cells in different kinds of 

 blood, appear to be subject to more variation than their forms. 

 With regard to the coloured corpuscles, they are somewhat more 

 numerous in venous blood than in that of the arteries. Of the 

 venous blood, that of the hepatic veins stands pre-eminent, con- 

 taining, according to Lehmann, many more blood-cells than the 

 portal blood, and it even exceeds in this respect the blood of the 

 jugular veins, in which also they are numerous above the average. 

 The colourless blood-cells, as has been shown by Funke and my- 

 self, are present in very large numbers in the blood of the splenic 

 vein. Here they sometimes present one nucleus, sometimes 

 several ; according to Hirt, the splenic artery contains these cells 

 in the proportion of 1 : 2200 red ones, while in the vein the pro- 

 portion is 1 : 60. The colourless blood-cells are also numerous, 

 according to Lehmann, in the blood of the hepatic vein, in whieh 

 they are distinguished by their very different size. I also have 

 observed this fact in many cases, but by no means always; and I 

 cannot regard it as an exclusive character of the hepatic venous 

 blood, seeing that, even in the portal blood (as Lehmann, too, 

 found in one case), and in the blood of the pulmonary veins, I 

 have found the same large number of colourless blood-cells, the 

 animals having been perfectly healthy. Elsewhere also, the colour- 

 less cells are more numerous in venous than in arterial blood 

 (Remak). In the superior vena cava and iliac vein of the dog, 

 Zimmermann observed that these cells had but one nucleus, while 

 in the inferior cava they had several. — On the peculiar large multi- 

 nucleated colourless cells, and on the biscuit-shaped ones with two 

 nuclei, which occur in the blood of the liver and spleen of young 

 animals see above, § 168. 



Many experiments have been made on the influence of various re-agents 

 upon the blood-globules, but some of the results obtained are of very little 



