ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 343 



situ with a 2 per cent, solution of bichromate of potassium or ammonia, 

 or with Miiller's fluid. The pieces of the nerve are then hardened 

 for twenty-four to forty-eight hours in the same solution, and are next 

 l>laced in 1/2 per cent, solution of silver nitrate. Less permanent 

 preparations may be obtained somewhat more quickly by adding to 

 10 parts of the first solution 1 part osmic acid. This is dropped on 

 in situ, and after ten or fifteen minutes, the nerve (sciatic of dog) 

 having been cut out, is divided into pieces 1 cm. long and placed in 

 the solution. The after treatment is as before. Examination must 

 be made every day for the first week to see if the time for silver 

 treatment have arrived ; a longer action of the silver than twenty-four 

 hours is of advantage. The rest of the procedm*e consists in teasing 

 out under alcohol a ad mounting in creosote-dammar. 



Preparing Nasal Mucous Membrane. * — Dr. E. Paulsen has 

 obtained very satisfactory results in his study of the glands of the nasal 

 mucous membrane by the use of Flemming's osmium mixture and 

 1 per cent, osmic acid, or Heidenhain's alcohol-hardening method, f 

 and of de la Field's hfematosylin solution for staining. Not only the 

 nuclei but the protoplasmic network were beautifully stained, while 

 the homogeneous intermediate substance remained clear. He dis- 

 tinguishes three kinds of glandular epithelium, (a) a portion exhibit- 

 ing all the characteristics of secreting mucous cells, (h) a second 

 portion resembling the cells of the albumen-glands, and (c) a third 

 uniting the characteristics of both. 



Chloral Hydrate for Preserving Lower Animals. J — Dr. A. 

 Fottinger has tried chloral hydrate for the preservation of lower 

 animals. Complete results were obtained with Alcyonella stag- 

 narum ; when all the polyps in a vessel containing 100 cc. of water 

 were fully expanded, some crystals of chloral hydrate were dropped 

 into the vessel ; these dissolved rapidly, and the substance was gra- 

 dually diffused through the water ; after ten minutes a little more 

 chloral was added, aud at the end of three-quarters of an hour the 

 whole colony had become insensible. When irritation results in no 

 retraction, the whole colony may be placed in alcohol without any 

 of the crowns of tentacles contracting or losing their normal form. 

 Dr. Fottinger is of opinion that the chloral has nothing but a narcotic 

 action, for they can recover from it, and their tissues are not affected 

 by it. The same result was obtained with the common star-fish, with 

 Doris stellata, and with other Polyzoa. Care must be taken that the 

 crystals do not come into direct contact with the object. The drug 

 succeeds very well with Nemertean worms. 



Collodion for Fixing on the Glass Objects to be preserved in 

 Alcohol.§ — Dr. A. Fottinger also describes his method of using 

 collodion to fix on to glass objects which it is intended to preserve in 

 alcohol. The animal, hardened by alcohol, is withdrawn from the 



* Arcli. f. Mikr. Anat., xxvi. (1885) pp. 307-21 (2 pis,). 



t See this Journal, v. (1885) p. 158. 



X Aruh. dc Biol., vi. (1885) pp. 115-25. § Ibid. 



