328 DR. E. KLEIN. 



cells; for those suh c mentioned, viz. the opaque or 'dis- 

 tinctly granular' gland-cells situated in the deeper parts of 

 the gland-tuhes contain a very dense network of fihrils, and 

 of course little of the interfibrillar ground-substance is seen, 

 hence the ' granular ' aspect of these cells. I have repre- 

 sented such a cell in fig. 7. In the flattened gland-cells de- 

 scribed suh b and the endothelial plates, sub d, the hyaline 

 ground-substance forms a formidable })ortion, the intracellular 

 fibrils forming a network with relatively wide meshes ; looked 

 at from the broad surface the cell-pla!e presents longitudinal 

 fibrils, in some places placed more closely than in others, and 

 anastomosing by lateral branchlets. When seen in profile 

 the continuity between the intracellalur and intranuclear 

 network is very distinct (figs. 9, 10, and 11). 



B 77ieme5ew^ery of a freshly killed newt (the black species) 

 is cutout together with the intestines and placed in a solution 

 of 5 per cent, chromate of ammoniri, where it remains for 

 twenty-four hours; it is then carefully c-ut into several portions 

 while under water, then cut off the intestine aiul left in water' 

 for about | — 1 hour ; after being stained in carmine, or picro- 

 carmine, or h£einatox\lin,it is ready for microscopic examina- 

 tion. For this purpose one or the other portion is floated 

 on an object-glass, and after having being spread out it is 

 covered with a covering-glass, a drop of glycerine having 

 previously been placed on the latter. It is necessary that 

 the preparation should be well spread out, but should not 

 be subjected to any undue pulling or other mechanical 

 injury, for this does invariably annihilate many of those 

 exquisitely delicate structural peculiarities that I am going 

 to describe below. But I must add that it requires not 

 much more than ordinary delicacy of handling in order to 

 obtain success, and I will likewise add that I know of no 

 more beautiful object in histology tiian a preparation of the 

 mesentery of newt prepared in the above manner, well stained 

 with haemaxotylin or doubly stained with picrocarmine first 

 and ha^nuitoxylin afterwards and well s])read out. Mounted 

 in glycerine the preparations preserve all their fine qualities. 



In our specimens we have to notice the following struc- 

 tures: — (1) the endothelium of the surface, (2) the ground sub- 

 stance, (3) unstriped muscle-fil)res (4) connective-tissue 

 corpuscles, (5) blood-vessels, and (6) nerve-fibres. 



I. Endotheliuia of iJie surface. 



In our specimens we find the endothelium of the surface, 

 when not detached from the subjacent membrane, repre- 

 sented as a transparent hyaline layer containing large 



