524: ABSOEPTION. 



strated ; 1 a fact which shows that these bodies may be devel- 

 oped de novo in the blood-plasma. 



Of these facts there can be no doubt ; and since the publi- 

 cation of the first volume of this work, additional experiments 

 upon the development of leucocytes in clear fluids have not 

 only confirmed the views which we adopted with regard to 

 the origin of these bodies in the blood and elsewhere, but 

 have defined more closely the conditions under which such 

 development may take place. We refer particularly to the 

 observations of Onimus upon the genesis of leucocytes and 

 upon spontaneous generation. 2 These experiments are all 

 the more striking in their application to the development of 

 the lymph-corpuscles, as they were made with the clear 

 fluid effused from the blood by vesication, and as recent facts 

 with regard to the relative anatomy of the smallest lymphat- 

 ics and the blood-vessels render it probable that the lymph 

 is in great part derived from liquid elements which pass out 

 of the blood by exosmosis. 



Onimus used the clear fluid taken without delay from 

 rapidly developed blisters, which he found ordinarily con- 

 tained no leucocytes, but which he carefully filtered in order 

 to remove all sources of error. The filtered liquid contained 

 no morphological element whatsoever ; but, on the other 

 hand, he found that if the liquid were allowed to remain for 

 an hour or more in contact with the dermis, it always con- 

 tained leucocytes and epithelial cells. Under these circum- 

 stances, even after filtration, the liquid contained a few leuco- 

 cytes ; but after six or seven hours of repose in a conical vessel, 

 the corpuscular elements gravitated to the bottom, leaving 

 the upper portion of the liquid perfectly clear. 



This liquid, entirely free from formed anatomical ele- 

 ments, was enclosed in little sacs formed of an animal mem- 



1 ROBIN, op. cit. Journal de la Physiologic, Paris, 1859, tome ii., p. 49, 



a ONIMUS, Experiences sur la Genese dcs Leucocytes et sur la Generation Spon- 



tanee. Journal de VAnatomie et de la Physiologic, Paris, 1867, tome iv., p. 47 



et seq. 



