526 ABSORPTION. 



plunging the glass tube in which it was contained into cool 

 water, while the other was kept at the ordinary temperature, 

 a little bicarbonate of soda being added to prevent coagula- 

 tion, it was found that leucocytes were developed as usual in 

 the fluid which contained its fibrin, and that none appeared 

 in the other. On placing the liquid with its coagulum en- 

 closed in a sac under the skin, it was found that after a time 

 the fibrin was redissolved, but no leucocytes made their ap- 

 pearance. 



The theory which has for its motto, omnis cellula e cellula, 

 receives no support from these experiments. Onimus added 

 to fluids which had been deprived of their fibrin, epithelial 

 cells and pus-corpuscles, but even after thirty-six hours, he 

 never found any additional development of corpuscular ele- 

 ments. Leucocytes added to fluids in which the fibrin was 

 unchanged did not seem to exert any influence upon the de- 

 velopment of new corpuscles. 



As regards the lymph, there is no fluid in the body which 

 is placed under conditions more favorable to the development 

 of leucocytes. It is enclosed in a system of vessels possess- 

 ing extremely thin walls, and undoubtedly subjected to active 

 osmotic currents. It contains, likewise, a considerable quan- 

 tity of fibrin; and the proportion of this principle has 

 always been found to influence the rapidity of the develop- 

 ment of white corpuscles. Its circulation is not very rapid, 

 and the obstacles to the current which are presented in the 

 lymphatic glands undoubtedly give time for the perfection in 

 the structure of leucocytes. It is in this way that the in- 

 crease in the number of leucocytes as the lymph passes from 

 the periphery to the larger vessels, and especially as the fluid 

 passes through the glands, can be explained. 



. From the fact that leucocytes are developed before the lym- 

 phatic system makes its appearance, that they are found in 

 lymph which has never passed through lymphatic glands, and 

 from the observations just cited showing their spontaneous 

 formation in an amorphous blastema, it is the inevitable con- 



