290 . CYTOLOGICAL METHODS. 



and mounted in balsam. Nuclei of ova, red ; heads of spermatozoa, bluish- 

 green. 



If sections of a gland of Helix be stained with methyl green and eosin, 

 the ova are stained rose colour, and the spermatozoa bluish green (HENNEGUY 

 in Traite des Meth. Techn., LEE ET HENNEGUY, p. 343). 



BENDA (Arch.f. mik. Anat. } xxx, p. 49 (Mammalia) ). Fix 

 in Flemming. Make paraffin sections. Stain them as follows : 

 Put them for twenty-four hours into concentrated solution of 

 neutral acetate of copper, kept at a temperature of about 40 C. 

 Wash them out well with water, and stain to a dark grey or 

 black tint in aqueous haematoxylin solution. Decolourise in 

 dilute hydrochloric acid (0'2 per cent.), until the sections ap- 

 pear of a fairly light yellow. The acid must now be neutra- 

 lised, which may be done by putting the sections back into 

 the copper solution until they turn of a bluish grey. Then 

 wash, dehydrate, and mount in balsam. See also the remarks 

 of PIERSOL, in Amer. Mon. Hie. Journ., 1887, p. 155 ; or in 

 Journ. Roy. Hie. Soc., 1888, p. 158; or Zeit. f. wiss. Mile., v, 

 4, 1888, p. 499. 



See also, of course, the numerous publications of V.LA VALETTE ST. GEORGE. 



