504 



spontaneous movement performed by the red corpuscles, whether within 

 or without the vessels, but at the same time I think that Cohnheim' s 

 theory does not account for the phenomenon under consideration. I 

 must hence leave the explanation of the fact for the future. Of the 

 fact itself there cannot be a shadow of doubt. 



Now, with regard to the phenomena just described as observed by 

 Cohnheim in the exposed mesentery, I may say in one word that I 

 have confirmed their accuracy in every particular ; I have seen and 

 measured the dilatation of the vessels ; I have observed the retardation 

 of the blood flow, the stasis in the capillaries, the accumulation of 

 white blood cells along the inner surface of the veins, and the exit of 

 the corpuscles through the vascular walls ; while I have never seen a 

 pus cell formed from any of the connective tissue or epithelial elements 

 of the mesentery or blood vessels. But there is one point untouched 

 upon by Cohnheim and almost all other writers on this subject, that is 

 the part played in inflammation by the lymphatic vessels and their con- 

 tents. The lymphatics in the mesentery of the frog run either as 

 sheaths surrounding, or as separate tubes immediately apposed to the 

 blood vessels. Now, on exposing the mesentery, these lymphatic 

 vessels are seen to contain clear lymph with leucocytes, indistinguish- 

 able from those of blood or pus, floating in it in variable number. Soon 

 the circulation of lymph becomes languid, and stops, while the corpus- 

 cles adhere about the outer side of the blood vessels, and perform 

 amaeboid movements ; so that the vessels are often at an early period 

 studded over with corpuscles which have not passed out from their in- 

 terior. The number of these corpuscles is quite insignificant, compared 

 to the number of those which subsequently pass out from the blood ; 

 but it will be observed always that those veins which are surrounded 

 by lymphatic sheaths are more thickly covered with pus corpuscles than 

 those which have no space about them — a fact the explanation of which, 

 I think, must be mainly sought in the lymphatic space, which, by afford- 

 ing room, facilitates the exit of corpuscles through the walls of the ves- 

 sels. 



Yery shortly after exposure, if the surface of the mesentery be exa- 

 mined, corpuscles will be seen floating in the fluid which moistens the 

 membrane. These, I think, float out from the lymphatic spaces under 

 the skin ; for on making a small opening in the skin, and examining 

 the fluid which flows from the wound, I have always found it to con- 

 tain leucocytes in greater or less number. The peritoneal fluid also 

 often contains white cells. The observations on the tongue of the frog 

 gave results precisely similar to those made on the mesentery. All the 

 pus was derived from the blood, the cells of the tongue remaining 

 throughout the inflammatory process unconcerned in the suppuration. 



These observations of Cohnheim have been repeated, and in all 

 essential particulars confirmed, by a great number of observers,- The 

 only attempt at a serious refutation of the fact of the emigration of the 

 blood cells was made a few months ago by Professor Balogh, of Pesth ; 

 but his objections are so futile, and his own observations so manifestly 



