40 American Quarterly Microscopical Journal. 



first, because there were no large oval corpuscles, the red glob- 

 ules proper, but only the small circular ones; second, because 

 they were fixed in the tissue, not floating to and fro in blood 

 serum; third, because I had seen many of them migrate. 



These phenomena were witnessed not by myself alone. Dr. 

 Bridge, Lecturer on Practice of Medicine, observed the emigra- 

 tion of several corpuscles; Dr. Danforth, Professor of Path- 

 ology, while unable to watch the process for a considerable 

 time, was convinced that emigration actually occurred; Miss 

 Mergler observed numerous red as well as white cells leave 

 the vessels. 



Having established the fact of the locomotion, therefore, it 

 remains to prove the dependence of that locomotion upon me- 

 chanical congestion rather than upon active hyperaemia. That 

 congestion existed was shown not only by the retardation of 

 the blood-current, and dilation of the vessels, but also by 

 oedema of the web, which became evident within twenty-four 

 hours. That the congestion was not '"active" was established 

 by two facts; first, the absence of all the phenomena of inflam- 

 mation, other than the amoeboid movements — /. e. the primary 

 acceleration of the blood-current, the subsequent retardation 

 with irregular contractions of the vascular walls; second, that 

 the discontinuance of the pressure on the vein was at once 

 followed by complete restoration of the circulation in the web, 

 whose irregularities, therefore, were dependent wholly on a 

 mechanical impediment and not upon any " nutritive irritation," 

 nor vascular spasm. 



This experiment has been repeated twice since the above 

 date. In both instances emigration occurred ; in one it began 

 within three hours after compression was made. In this case 

 the pressure exerted exceeded somewhat that made in the first 

 instance. 



Now, the value of these facts depends upon one's ideas of 

 pathogenesis. If he believes, with Billroth, that connective 

 tissue is developed solely from migrated blood corpuscles, he 

 has a key at once to the connective tissue hyperplasia of the 

 skin and venous walls which accompanies a varicose condition 

 of the veins. For the mechanical congestion necessarily pres- 

 ent must result in the emigration of blood corpuscles into the 

 surrounding tissues, and these are developed, says Billroth, 

 first into spindle cells, and finally into complete connective 



