On Diapedesis. 83 



integrity being broken, as proved by Graham, and have hkened the 

 process to the passage of frog's blood-corpuscles through the much 

 smaller interstices of a fine filter. Erichsen thinks that the nerves 

 and other tissues have an important influence. 



In silver stained preparations the corpuscles always he in the 

 inter-endothelial lines. 



The coloured corpuscles, which can also be observed to migrate, 

 are either taken up by the colourless corpuscles, or are disintegrated, 

 producing pigmentation. 



IV. Intimately connected with this subject is the origin of pus. 

 We now know that migrated blood- corpuscles form the chief 

 source ; but, if we carefully review the subject, we shall agree 

 with Dr. Payne's remarks on the subject before the Medical Micro- 

 scopical Society, viz. that " Virchow's idea of the origin of 

 pus, though now old-fashioned, is far from being overturned by 

 Cohnheim," for the observations of Strieker and Eecklinghausen 

 go directly to prove origin, in part at least, by prohferation of 

 connective-tissue corpuscles. 



