QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 409 



the silver nitrate has penetrated more deeply, one may even 

 see that the endothelial layer extends to the canalicular 

 system, and is continuous with the endothelium of the tubes. 

 Hoyer and Schweigger-Seidel have noticed the dark lines seen 

 in silver preparations of the cornea, but have not considered 

 them to show the presence of an endothelium. Rollett 

 thinks that these lines can only be seen in the cornese of young 

 animals, whose fibrillar substance is in course of development, 

 but Dr. Thin has observed them in the adult also. Further, 

 by using both silver nitrate and gold chloride he has seen 

 that the nerves coloured by the latter reagent are contained 

 in the cavity of the lymphatic, which they fill almost com- 

 pletely ; but a narrow, clear space can be distinctly seen be- 

 tween the nerve and the wall of the lymphatic. The branches 

 of the nerves given oif from the chief trunk have a similar 

 relation to the smaller lymphatic vessels in which they are 

 contained. 



7. On the Structure of Lymphatic Glands. — Bizzozero 

 (separately printed memoir) has investigated the reticulum 

 of the lymph-paths in the dog, man, rabbit, and calf. This 

 is commonly described as consisting of homogeneous or deli- 

 cately striated fibres, with here and there a nucleus, or in 

 some places as composed of stellate connective-tissue- 

 corpuscles, communicating with each other and with the 

 fibres by numerous processes. Billroth (' Virchow's Archiv,' 

 vol. xxi, p. 347) had already stated that in chronically in- 

 flamed glands the nuclei had partly developed into spindle 

 cells, which were merely applied laterally to the fibres. This, 

 however, appears to be the normal condition, according to 

 Bizzozero. In fine sections of hardened glands of the dog, 

 which have been freed from lymph-cells by shaking in water, 

 the cellular elements of the reticulum can be recognised as 

 spindle-shaped, stellate, or flattened cells, with a coarsely 

 granular protoplasm, often containing fat- and pigment- 

 granules. The nucleus is oval, finely granulai-, and contains 

 one or two shining round nucleoli. Their number varies 

 with the time for which the preparations are shaken. At 

 first there are large numbers of them, even in adult animals, 

 but the longer the sections are shaken the more is the reti- 

 culum freed from them, so that in good preparations they 

 may all be dislodged without injury to the adenoid network. 

 This fact is enough to prove that the cells are simply applied 

 to the fibres — that they are contiguous to but not continuous 

 with them. This can also be seen with high powers in 

 sections in which the cells are still present. The cell may 

 then be seen either to surround a fibre, which then becomes 



