372 Journal of Applied Microscopy. 



ANIMAL BIOLOGY. 



Agnes M. Claypole. 



Separates of papers and books on animal biology should be sent for review to 



Agnes M. Claypole, Sage College, 



Ithaca, N. Y. 



CURRENT LITERATURE. 



Cajal, Ramon y. Algo sobre la signification A technical point is of particular interest 



fisiologica de la neuroglia. Rev. trim. in this connection. The author finds 



microgr. t. II, fasc. i, pp. 33-47, 1807. Ab- ^, , -.tt • , ^■ • , 



stract in Zeit. f. wiss. Mikros. 15: p. 365. that Weigert's neuroglia stain does not 



differentiate neuroglia fibers alone, but 

 also more or less non-medullated nerve fibers. Hence, a few axis-cylinders of 

 the stellate cells of the molecular layer of the cerebellum, and some of the basket 

 fibers of the purkinje cells, are brought out. The method, however, gives a com- 

 plete representation only of the neuroglia. The complex lateral processes of 

 Bergmanni's fibers, the delicate branches of the cells of the molecular layer, the 

 thick processes of epithelial cells do not stain at all. The author considers 

 Weigert's method most valuable for the neuroglia of the alba. a. m. c. 



Apathy, Stefan. Hjematein Method. Mittheil. This method is best adapted to inverte- 

 aus der Zool. Stat, zu Neapel. 12: p. 712- ^^^^^ ^- ^^^ ^e used for either 



71b, 1 097. ' 



fresh or salt water forms. The solution 



for staining is made by pouring together equal volumes of (a) one per cent. 



haematein in seventy per cent, alcohol ; (/;) concentrated glycerine ; (r) a mixture 



of distilled water with one pro mille salycilic acid, three per cent, acetic acid, 



and nine per cent. alum. 



Fixation in sublimate solution (concentrated solution of sublimate in one-half 

 per cent, sodium chloride) is best for demonstrating the nerve cell or the plexus, 

 although Lenker's fluid, picric acid, or other fixing agents may be used. If the 

 material is not to be stained at once, it should be left in ninety per cent, alcohol. 



The specimen should not exceed five millimeters in. thickness, and should be 

 stained in toto if small enough. Regardless of size, material must be left in the 

 stain at least forty-eight hours, although three days is not too long, and it may 

 be left longer. After staining, wash in distilled or double distilled water, fre- 

 quently renewed. The duration of the washing is the most difiicult point, but 

 once determined, it may always be kept the same. It depends upon the size, 

 the condition of the tissue, and the position of the nervous system. 



Neurofibrils are stained dark blue to black, although if left too long every- 

 thing stains, but the stain may be washed out with distilled water, except from 

 the nucleus. If the water inclines to be acid, wash in slightly alkaline water, 

 then two hours in distilled water. From distilled water, change directly to a 

 quantity of absolute alcohol, and imbed in paraffin, celloidin, or glycerine jelly, 

 and mount in balsam. For paraffin imbedding, chloroform should be used. In 

 celloidin imbedding, avoid much exposure to the light. To imbed in glycerine 

 jelly, place in the jelly immediately after washing in distilled water, keep at an 

 even temperature until all the water is expelled, pour into a mold, place it in 

 absolute alcohol, and cut in absolute alcohol. E. M. Brace. 



