BY DR. KLEIN. 55 



also clear, but the interstitial substance is violet ; whereas in 

 the dull red parts, there are bluish or dull red corpuscles on a 

 clear groand. Both in the first and in the second, there are 

 transitions to the intermediate parts, i. e., the nearer the part 

 observed is to the edge of the dull violet-red parts, the more 

 possible is it to make out that the network of protoplasm 

 occupies the canalicular system. It is always possible to find 

 points where the processes of protoplasm stretch from these 

 parts into clear canaliculi. 



Branched Corpuscles of the Tail of the Tadpole. 

 Another object in which it is easy to demonstrate the 

 branched corpuscles is the tail of the tadpole. In this organ, 

 when prepared in the fresh state, as above directed, a very 

 beautiful network of pale protoplasm, in a hyaline interstitial 

 substance, may be demonstrated. The network consists of 

 nucleated cells, which communicate with one another by den- 

 dritic processes. It is most dense near the edges and toward 

 the tip of the tail. In order to obtain preparations of this 

 structure, it is best to place a portion of the organ of a tad- 

 pole (in which the posterior extremities have begun to sprout) 

 in half per cent, solution of chloride of gold for from thirty 

 to forty minutes. The preparation having been placed for 

 twenty-four hours in distilled water and exposed to light, the 

 epithelium of one side must be removed. For this purpose 

 the organ must be fixed by a needle in the middle line close to 

 the cut end : the epithelium, with the plexus of nerves and 

 bloodvessels of one side, can be stripped off with the fine- 

 pointed forceps in the form of a membrane a process which 

 is much facilitated by first placing the preparation for fifteen 

 minutes in absolute alcohol. The separated structures are 

 then covered in glycerin. Such preparations are of great 

 value, serving not merely for the demonstration of the cells 

 with which we are now concerned, but also, as will be seen, 

 for the study of the structure and development of the capil- 

 lary bloodvessels, of the most minute nerve fibres, and the 

 relation of the lymphatic vessels to the connective tissue 

 elements. The description and mode of demonstration of the 

 branched cells of the serous membranes will be given in the 

 chapter on the lymphatic system, in connection with which 

 they are of most importance. 



Branched Corpuscles of the Skin. In order to de- 

 monstrate the branched cells of the cutis (or of the mucosa), 

 it is best to snip off folds or ribands from the fresh structure 

 with the curved scissors. These are placed in half per cent, 

 solution of chloride of gold until they acquire a distinctly 

 yellow tinge. They are then transferred into distilled water 

 until they are tinged dark violet and finally hardened in ordi- 

 nary alcohol. Sections must then be made parallel to the 



