120 CIRCULATING FLUIDS: 



siders tliat the blood-corpuscles are formed in the lymphatic 

 glandsj and conveyed by the ductus thoracicus into the blood. 

 He states that the chyle which is found in the vessels issuing 

 from the glands, contains clear, round, oily vesicles, and 

 granular lymph-corpuscles. The diameter of the granular 

 lymph- corpuscles in horses and rabbits varies from "0005 to 

 •0008 of a line ; and they are so similar to the nuclei of the blood- 

 corpuscles, as to render it very probable that the latter are de- 

 rived from them. In the lymph of the ductus thoracicus of 

 rabbits and horses, we find actual blood-corpuscles, as well as 

 the transparent and granular lymph-corpuscles ; these blood- 

 corpuscles, however, possess more tender, and not perfectly 

 flattened capsules, and a much smaller amount of colouring 

 matter than when they have arrived at maturity. They are 

 consequently paler and more transparent than at a subsequent 

 period, and the nucleus may be inclosed more or less closely 

 in the capsule. The lymph-corpuscles and the nuclei of the 

 blood-corpuscles present a very close analogy, for they both 

 vary in size, and, to use Schvdtz's own words, " it cannot be 

 doubted that the blood-corpuscles are produced by the forma- 

 tion of a coloured capsule around the lymph-globules.^^ ^ 



These blood-corpuscles could not have been transmitted 

 there by blood-vessels; their difference from the mature cor- 

 puscle, and their slight amount of colouring matter, are opposed 

 to such a supposition. Since lymph-corpuscles also pass into 

 the blood, the formation of blood-corpuscles from them in the 

 blood-vessels cannot be denied ; it may however happen that 

 they are again conducted by the blood to the lymphatic glands, 

 where their metamorphosis is completed. In a more recent 

 work- on the Blood,^ Schultz states that the coloui'ed capsule of 

 the blood-corpviscle is principally formed in the process of re- 

 spiration. There is much in favour of this \dew, for we know 

 that the blood can only obtain its nutriment through the 

 ductus thoracicus, and it seems obvious that the conditions 

 necessary for the formation of the blood- corpuscles must be as- 

 sociated with the circumstance of the derivation of the nutriment 

 from this source. ISIoreover, there can be no doubt that in conse- 



» L. c, p. 45. 



* Ueber die gehemmte Auflosungund Ausscheidung der verbrauchten Bhitbliischen. 

 Hufeland's Journal, April 1838. 



