328 Coinmunication of Blood-vessels with the Lymphatics. [June 16, 



gelatine from the blood-vessels, also exhibited a phenomenon similar to that 

 observed in the organs just mentioned. 



Sections taken from this gland and examined with the :^-inch objective, 

 showed that from the capillaries are given off fine processes which break 

 up into a network among the cell-elements of the vesicles, and, furthermore, 

 that this network is in communication with the lymphatics which lie in the 

 inter vesicular parts of the gland. In addition to this, however, there are 

 communications between the capillaries and lymphatics in the stroma itself. 



The processes which emerge from the capillaries in the stroma of the 

 thyroid as well as in the fibrous tissues of other parts, such as the membrana 

 nictitans of the cat, bear a very strong resemblance to connective-tissue 

 corpuscles ; and such the author considers them to be in these parts. But 

 as these tubular processes can be shown by injection to form a plexus in 

 the retina (cat), to be connected with the nuclei of the capillaries, the cor- 

 puscles of bone (perch and mouse), and the fusiform bodies found among 

 the fibrillse of muscle (frog), as well as with the cells of connective' tissue 

 and its modifications, it has appeared that the whole of these structures 

 belong to one system of vessels. This system the author has named, pro- 

 visionally at least, " Diaplasmatic," because, on account of the extreme 

 minuteness of its channels, it can only allow of the passage of the liquor 

 sanguinis. 



To designate the whole of these minute vessels lymphatics would, he 

 considers, at the present time be somewhat premature, because those of 

 muscular fibre and of bones, and others which will be mentioned immediately, 

 have not been observed to join recognizable lymphatic trunks ; and moreover 

 it would seem by no means improbable that some of them may both com- 

 mence and terminate in the blood-vessels, thus constituting what might be 

 styled an intercapillary plexus ; or they may even have a triple connexion, 

 viz. with the arterial capillaries, the lymphatics, and with the venous capil- 

 laries or the veins. 



The position in which the diaplasmatic network may be most readily 

 demonstrated, both with and without injection, is in the mucous membrane 

 of the palate of the frog or toad. In this part, when the viscid mucus and 

 the ciliated 'epithelium have been removed, there may be seen with the 

 1-inch objective, a very minute granular nucleated network, in each mesh of 

 which is placed a globular nucleated cell. The membrane consists, there- 

 fore, of three layers — of a superficial ciliated layer, next of a granular nu- 

 cleated plasmatic network, and lower still of a basement layer of globular 

 nucleated cells. The processes of the middle granular plexus extend not only 

 in the horizontal direction, but also upwards between the ciliated cells, and 

 downwards between those of the basement layer, where they become con- 

 tinuous with the blood-vessels lying in the fibrous tissue beneath. This 

 connexion with the blood-vessels, the author says, he has been able to make 

 out by means of injection in the palate and oesophagus of the frog and 

 toad, as weli as in the mucous membrane of the eyelid of the latter animal. 



