ZOOLOGY AND BOTANY", MICROSCOPY, ETC. 241 



Histologfy of Uterine Mucosa of Viviparous Sharks and Rays.* — 

 A. Brinkiuann fixed the material in the following solutions : (1) Saturated 

 aqueous solution of sublimate in normal salt water, plus 3-5 p.c. acetic 

 acid. (2) 10 p.c. formalin (1 part commercial formalin, plus 8 parts 

 water). (3) Flemming's strong mixture. (1) Hermann's mixture. 

 (5) A mixture of equal parts of No. 1 without the acetic-acid and of No. 2. 

 The last solution gave very satisfactory results. As often as possible 

 the material was pinned to cork, and in order to keep the uterus in its 

 natural shape, P. Mayer's method for fixing intestine was adopted. A 

 glass tube was tied to both ends of the uterus. To the tubes were fixed 

 pieces of rubber tubing supplied with pinchcocks, so that fluid could be 

 run through or retained at will. The uterus was first washed out with. 

 0"75 salt solution and then treated with fixative, usually 10 p.c. formalin. 

 After about 20 minutes this was followed by upgraded alcohols. After 

 dehydration the pieces were treated with toluol and then imbedded in 

 parafiin. The sections were stained with h^emalum, carmalum, gentian, 

 safranin and iron-hi«matoxylin, the contrast sttiins being light green, 

 eosin, acid-fuchsin and picric acid, indigo-carmin and picric acid, and 

 orange Gr (1 part 1 p.c. solution plus 25 parts 2 p.c. alum-water). For 

 mucus staining, mucicarmin, thionin and toluidin-blue. 



Fixation of Nerve-cells.f — Y. Manouelian, in an article on the 

 mechanism of the destruction of nerve-cells, remarks that the Nissl 

 method (fixation with 96 p.c. alcohol), though weU suited for the 

 demonstration of the chromophilous particles, causes considerable shrink- 

 age of nerve-cells, and in order to obtain good and reliable preparations, 

 recourse must be had to mixtures of alcohol, formalin, or sublimate with 

 fluids like acetic acid which balance the shrinkage by their property of 

 causing the protoplasm to swell. These fixative mixtures have the 

 further advantage of not being detrimental to staining reagents. The 

 specimens depicted by the author were fixed in Gilson's fluid (alcohol, 

 acetic and sublimate) and stained with magenta and picro-indigo-carmin. 



Studying Naididse.J — L. B. Walton made drawings from Living 

 specimens with the aid of the camera-lucida. The most satisfactory 

 rnethod was that of transferring the Naid from the culture, by means of 

 a pipette, to a watch-glass, and subsequently to a drop of water on a slide, 

 then placing over the drop a cover-glass, the margin of which was 

 supported by a thin wooden bridge. After a time the specimens, with- 

 out undue compression, would become quiet, and outline drawings could 

 be made with the camera. 



Specimens to be mounted were fixed with hot sublimate-alcohol 

 (sublimate 10 grm., absolute alcohol 100 c.cm., distilled water 100 c.cra., 

 acetic acid 2 c.cm.), stained in borax-carmin, and eventually transferred 

 to balsam, while those sectioned were stained in hfematin I A (Apathy), 

 or in iron-hfematoxylin (Heidenhain), after fixation in cold sublimate- 

 alcohol. The index of refraction of balsam approaches so closely the 



* Mit. Zool. Stat, zu Neapel, xvi. (1903) pp. 365-408 (3 pis.). 

 t Ann. Inst. Pasteur, sx. (1906) pp. 859-68 (1 pL). 

 X Amer. Naturalist, xl. (1906) pp. 683-706 (12 figs.). 



April 17th, 1907 a 



