COKPUSCTTLAB ELEMENTS OF THE LYMPH. 523 



granular and quite opaque. They present the same adhe- 

 sive character in the lymph that we have noted in the blood, 

 and frequently are found collected in masses in different 

 parts of the lymphatic system. 1 Treated with acetic acid, 

 the corpuscles generally become swollen, and are rendered 

 very transparent, then presenting from one to four or five 

 nuclear concretions in their interior. In all other regards, 

 these bodies present the same characters as the leucocytes of 

 the blood, and need not, therefore, be further described. 



We have already alluded to the fact that the lymph-cor- 

 puscles are more abundant in the larger than in the smaller 

 vessels ; and "that they have been thought to be particularly 

 numerous in the vessels coming from the lymphatic glands. 

 It is nevertheless true that corpuscles exist even in the 

 smallest vessels, and they are sometimes quite abundant in 

 lymph which has not passed through any glands. These 

 considerations naturally lead to the theory of the develop- 

 ment of leucocytes in the lymphatics, as well as in the or- 

 dinary vascular system, particularly as the constant dis- 

 charge of lymph and chyle into the blood-vessels renders it 

 more than probable that most of the leucocytes found in the 

 blood are derived from the lymph. 



The late researches of Robin, and others, by whom his 

 observations have been somewhat extended, have conclu- 

 sively demonstrated that leucocytes may be developed, under 

 proper conditions, in a clear structureless blastema, without 

 the intervention of any glandular organ ; and, furthermore, 

 it is not necessary that the blastema should be enclosed in 

 any system of vessels. These facts refute completely the idea 

 that the lymph-corpuscles are formed either by the lymphatic 

 glands or by the walls of the lymphatic vessels. Observa- 

 tions have also shown that leucocytes exist in the blood ot 

 the embryo before any lymphatic vessels can be demon- 



1 ROBIN, Sur quelques Points de VAnalomie et dc la Physiologic des Leucocytes 

 ou Globules blancs du Sang. Journal de la Physiologic, Paris, 1859, tome ii., p. 

 44. 



