ON INTER-CELLULAR BRIDGES IN COLUMNAR EPITHELIUM 267 



Hère and there a leucocyte may be seen in process of migration through 

 the epithelium. As the body of the leucocyte is much larger than the inter- 

 vais between the bridges, it must, in passing through, either break thèse 

 connections across, or stretch them and push them aside. In the first case 

 we must suppose, if the bridges are broken across, that they reunite again, 

 otherwise after an extensive migration of such cells (and this is very com- 

 mon especially in the small intestine) so many bridges would be destroyed, 

 that the cells would become practically isolated; but in ail the préparations 

 I hâve examined I hâve found no trace of such isolation, the bridges being 

 perfect everywhere. 



It seems to me therefore, that the second hypothesis, that the bridges 

 are stretched and pushed aside — is the more probable — the more so 

 that the leucocytes may be seen to be surrounded by a ring of bridges, appa- 

 rently unbroken, which form a temporary pseudocapsule for them ; and one 

 can readily conceive how the elasticity of the bridges enables them to regain 

 their original length. 



Ide (1) states that the intercellular bridges of stratified squamous epi- 

 thelium are elastic in nature and inclines to the view that the leucocytes 

 produce stretching of them during their passage through thetissue, he feels, 

 however, unable to make a definite statement on that point. ,« 



I also endeavoured to détermine whether the state of the stomach had 

 anything to do with the appearance of the bridges, and for that purpose 

 examined a number of stomachs taken from cats killed at différent periods 

 after a full meal, but hâve come to the conclusion, that the bridges are 

 least visible when the cells are rendered turgid by the absorption of lymph, 

 and become most visible when the animais hâve been deprived of food and 

 water for a considérable time. When the lymph spaces between the cells 

 are full of a lymph rich in proteid matters, this tends to become coagulated 

 by the fixing agents, and remaining in a stainable condition in the lymph 

 spaces, diminishes the contrast between them and the neighbouring cells, 

 thus producing a more homogeneous appearance throughout the sections. 



The points above detailed will therefore be rnost easily demonstrable 

 in animais that hâve fasted for a considérable time. 



The inter-cellular bridges are as distinct at the pyloric end of the 

 stomach and in the ducts of the cardiac and pyloric glands as they are at 

 the cardiac end of the stomach. 



The above description applies especially to the appearances presented 



(1) Ide, M. : Nouvelles observations sur les cellules épithéliales ; La Cellule, t. V, p. 336. 



