

VESSELS. ARTERIES. VEINS. CAPILLARIES, ETC.- 83 



form its capillary network, there are very few. There 

 is found also, in the lacteals, a variable quantity of 

 spherical granules of an oily nature, which are derived 

 from the food, and which are very early to be seen in 

 the true lymphatics. 



Lymph, also, coagulates when it escapes from its 

 containing vessel, forming a clot, identical in its com- 

 position to that of the blood including, of course, 

 no red globules. Kolliker asserts that lymph never 

 contains red globules, and that those occasionally 

 found in it got there in consequence of the rupture of 

 a blood-vessel. 



The formation of the red blood corpuscles in the F 1 f e t mofred 

 embryo is effected, as we have already stated, by 

 transformation of the primordial or embryonic cells 

 which occupy the centre of the blood-vessels whilst 

 in process of development. These cells are not at first 

 distinguishable from the embryonic cells by which 

 they are surrounded, but they soon become infiltrated 

 with haematine, flatten out into discs, and their nuclei 

 tend to disappear. They multiply by the process of 

 cleavage. In the adult the increase in number of red 

 corpuscles seems to take place at the expense of the 

 lymph globules, which become disc-like in shape, and 

 charged with haematine, whilst at the same time 

 their nuclei are absorbed. Kolliker, relying upon 

 what he has observed in the lower animals, asserts 

 that this is the mode of development of the red cor- 

 puscles of the blood in man. 





