THE BEGINNINGS OF LIFE. 221 



that there is a strong anatomical resemblance a per- 

 fect similarity in fact between the earlier stages of 

 all kinds of pus and mucus corpuscles, and the white 

 corpuscles of the blood \ He accordingly uses the word 

 c leucocyte' as a generic appellation for the various 

 living units of this type which are to be met with 

 either as physiological or pathological tenants of the 

 different fluids of the body. And although it is not 

 denied that such units are capable of undergoing rapid 

 multiplication by processes of fission and gemmation, 

 they are, as Robin maintains, also capable of being 

 evolved de novo in the several fluids of the body. 



M. Onimus 2 has lately recorded some very carefully 

 conducted experiments made for the purpose of obtain- 

 ing more satisfactory evidence as to the mode of origin 

 of leucocytes. He found that when serosity was 

 taken as soon as possible from a rapidly formed blister, 

 and then filtered, no leucocytes, and only a very few 

 epithelial scales, were recognizable by the aid of the 

 microscope on the filter; whilst the fluid which had 

 passed through was never found to contain any formed 

 element, leucocytic or epithelial 3 . But, whenever the 

 serosity had been taken from the blister one hour 

 after its effusion, then, almost invariably, a certain 

 number of leucocytes were found on the filter, and at 



1 ' Sur quelques points de 1'Anatomie et de la Physiologic des Leuco- 

 cytes ou Globules Blancs de Sang.' Brown-Sequard's ' Journal de la 

 Physiologic,' torn. ii. 1^59 p. 41. 



2 ' Journal de 1'Anat. et de la Physiol.' 1867. 



* The magnifying power employed, is unfortunately not stated. 



