( 229 ) 

 PEOGEESS OF MICEOSCOPICAL SCIENCE. 



The Lymphatics of the Lungs. — An investigation into these struc- 

 tures has been recently undertaken in M. Chi'zonszczewsky's labora- 

 tory at Kiew, by Herr J. Sikorsky. The results have been published 

 in the ' Centralblatt ' of December 3rd, 1870, and are abstracted in 

 a recent number of the 'Lancet': — The method adopted consisted 

 in the injection of a watery solution of ammonia into the lungs of 

 living cats and dogs, and the subsequent examination of the paths 

 pursued by the tinted fluid, the lungs being at once removed from the 

 body and frozen, and the blood-vessels being in most cases injected 

 with a solution of gelatine tinted blue. In such experiments it was 

 found that, in opposition to the efiect produced in dead animals, 

 neither the intercellular substance, nor the cell formations, not even 

 the columnar epithelium of the bronchia, with which the carmine 

 solution must have been in direct contact, became tinted. The com- 

 mencement of the lymphatic system was not exactly the same in the 

 bronchia and the alveoli of the lungs. In the bronchia the epithelium 

 generally remained uncoloured ; but between the columnar cells were 

 special structures, very similar in form to these cells, and staining 

 strongly with carmine. From these structures minute canals pene- 

 trated perpendicularly to the surface of the mucous membrane, and 

 formed a close plexus in the submucosa, and partly also in the 

 mucosa, from which larger trunks originate, which accompany the 

 bronchia to the roots of the lungs. In the alveoli of the lungs, on 

 the other hand, a peculiar plexus, composed of tubes and nodal dilata- 

 tions, is found ; the latter are triangular, stellate, or irregular cavities, 

 which are again connected with the lumen of the alveoli by means 

 of very fine tubules. The lymphatic plexus of the alveoli gives 

 origin to larger vessels, which accompany the veins to the roots of 

 the lungs. This system constitutes the so-called deep plexus of 

 lymphatics of the lungs. The superficial plexus arises from the 

 subj)leural alveoli. The trunks pass into the pleura, and then into 

 the pulmonary ligaments. 



The Origin and Nature of Fat. — In the ' Transactions of the Vienna 

 Koyal Academy,' Herr Toldt has recently published some very interest- 

 ing observations : In opposition to the statements of Virchow, who 

 maintains that fat-cells are to be regarded as the cells of connective 

 tissue filled with an oily fluid, and are therefore constantly associated 

 with this tissue, Toldt gives as the general results of his inquiries 

 upon the intra-spiual fatty tissue that this, at least, is an organ of a 

 peculiar nature, which neither in regard to its structure nor function 

 can be included amongst the connective tissue formations. In order 

 further to demonstrate that adipose tissue is independent of connective 

 tissue, he refers to the characters and relations of fat in the Batrachia. 

 The masses of fat that surround the uro-genital apparatus of these 

 animals in the larval state consist of large, round, transparent nu- 

 cleated cells, not separated by any intervening substance except blood- 



