BY DR. KLEIN. 125 



made out. It is true that, among the small mosaic of certain 

 channels, there are dark or clear spots which have been de- 

 scribed by authors as stomata, with which, however, their 

 relation is very doubtful. 



Method of Demonstrating the Stomata. To demon- 

 strate them, the abdominal cavity of a rabbit just killed must 

 be opened, a ligature passed round the cardia, and another 

 round the bunch of vessels leading to the porta. This done, 

 the abdominal viscera, excepting the liver, may be cut away 

 and removed ; great care being taken not to draw upon the 

 diaphragm in any part of the operation. The liver being then 

 held aside, water is poured over the abdominal surface of the 

 diaphragm. After a few seconds, silver solution is poured 

 once or twice over it in the same way, and the whole left to 

 itself for a few minutes. It is then again washed with water, 

 after which it may be cut out and subjected to microscopical 

 examination. In preparations so obtained rows of stomata 

 may be seen, both over the superficial interfascicular lymph- 

 atics, and occasionally in situations which correspond to the 

 circular ones ; which, exhibit, in all respects, the same anato- 

 mical characters as those of the septum cisternse magnae in the 

 frog. Each canal leading from a stoma to a subjacent lym- 

 phatic is seen to be lined by small granular cells of the same 

 character as those already described as guarding the orifice. 

 They are particularly distinct where the canal opens into the 

 lymphatic, especially in those canals which are in communica- 

 tion with the tymphatics of the deeper, i. p., the pleural layer. 

 The lymphatic sj'stem of the diaphragm is divisible by the 

 middle line into two similar halves. Each half may be again 

 divided, according to the direction in which the lymph flows, 

 into two parts an anterior and a posterior. The anterior 

 system is made up of the large lymphatic vessels to be found 

 on the pleural side, all of which converge towards the sternum, 

 discharging themselves into a single large lymphatic trunk, 

 which stretches in the form of an arch along the outer edge of 

 the sternum, accompanying the internal mammary artery and 

 vein. 



Each of the trunks as it ascends divides into a plexus of 

 smaller vessels, by which the lymph is conveyed to the sternal 

 glands. These lymph vessels receive their tributaries from 

 the external border of the anterior half of the centrum, and 

 from the anterior third of the external border of the posterior 

 half. The lymphatic vessels of the remainder of the diaphragm 

 belong to the posterior system, which opens on either sidr by 

 a short, wide lymphatic trunk, which joins the thoracic duct 

 just after the latter has entered the throracic cavity. The 

 lymphatic interfascicular channels are all to be regarded as 

 tubes of communication between the two systems. From 



