THE BLOOD. 123 



Kolliker, who have seen the transformation of white globules 

 into red produced even outside the organism, in blood kept 

 at the temperature of the living body, in contact with a 

 moist atmosphere. On the other hand the study of the 

 blood in the animal series shows all the transitions between 

 the two kinds of globules. Rouget has shown what they are 

 in the case of the invertebrate animals, the sipunculi. In the 

 inferior vertebrate animals, particularly the tadpole (Kolli- 

 ker, Rouget), we observe the transformation of the lymphatic 

 corpuscles into colored globules, provided with a nucleus, 

 the coloring matter being first deposited under the form of 

 granulations, and then spreading uniformly, throughout the 

 globules. Rouget has observed the same transformation in 

 the embryo of rabbits ; here the nucleus diminishes, and at 

 length disappears, while the coloring matter is deposited 

 first in patches, and afterwards generally diffused. Finally, 

 there have been found in the thoracic duct, and even in the 

 pulmonary veins (Kolliker) young red globules in an inter- 

 mediate stage between the white globules and the perfect 

 red. As to the indirect proofs of this transformation, it will be 

 sufficient to remark that the lymphatic glands and the spleen 

 are continually pouring white globules into the current of 

 the blood. Now, as we do not find that their number in- 

 creases in the blood, and know of no proof of their being 

 destroyed, we are forced to conclude that they disappear by 

 being changed into red globules. Finally, these red glob- 

 ules must have had an origin, and been derived from a pre- 

 existing cell, for they exhibit globular forms which are already 

 old, the loss of the nucleus and the presence of coloring 

 matter being taken into account ; if we accept the theory of 

 the genesis for the production of the white globules, which 

 are elements in an early stage, we cannot do the same in 

 the case of the red, which are old forms of elements : the 

 early stage of the red globules can be represented only by 

 the white. 



In their mature condition the red globules themselves ex- 

 haust a part of the oxygen with which they are charged, 

 the presence of this oxygen being necessary to their vitality 

 and to their form. In making experiments, whenever it is 

 desired to filter blood, care must be taken to introduce into 

 the liquid a current of oxygen, which prevents the solution 

 of the globules in the liquor. When destroyed in the sys- 

 tem, the globules leave what are evidently the products of 

 their decomposition. It is true that there are hardly any 



