MILLER — CONTRIBUTIONS FROM ANATOMICAL LABORATORY. 241 



stomata and stigmata described by Arnold; and, after referring 

 to the experiments of Cohnlieim, says: 



"The number of stomata seem consequently to depend on the num- 

 ber of blood corpuscles which have passed through the walls of the 

 vessel, and this observation suggests the thought, contrary to the con- 

 clusions of Arnold, that the stomata are not preformed but that they 

 are produced within the capillaries by the passage of corpuscles." 



Although Arnold (1) accepts the existance of stomata, he does 

 not believe in their open communication with the lymphatic sys- 

 tem. Rawitz (18) assumes the passage of leucocytes, but does 

 not seem to be able to convince himself that there are free open- 

 ings ; he suggests that there are "at least soft places." 



Tourneaux (23) believes the so-called stomata are artifacts, 

 and says that he did not succeed in verifying a connection be- 

 tween the body cavity and the lymph-spaces. His conclusions 

 were based upon experiments with starch and carmine granules, 

 neither of which, he asserts, will penetrate into the lymph-ves- 

 sels when introduced into the body cavity. He concludes by 

 saying that the lymph cavity can be filled and the body cavity 

 remain empty, or vice versa, without the passage of the starch or 

 carmine from the one to the other. 



The conclusions of Tourneaux are of special interest because 

 they directly contradict the views given above ; for most of the 

 authors mentioned, base their opinions upon the statement that 

 when solutions holding starch or colored granules in suspension 

 are injected into the abdominal cavity, the granules will after 

 some hours be found in the superficial lymph-vessels. 



Muscatello (15) maintains that the central tendon of the 

 diaphragm is the only place where stomata may be found, and 

 even here they are somewhat doubtful. From the standpoint of 

 absorption and diapedesis it is difficult, indeed, to see why 

 stomata should be necessary to absorption in one region of a 

 serous cavity and not in another. If leucocytes can pass through 

 the walls of the blood and lymph-vessels without the presence of 

 stomata, it does not seem a good argument to say that they are 

 necessary elsewhere ; besides if stomata are a sine qua non to ab- 

 sorption they certainly ought to be found in the intestine. 



