COLLODION AND OTHKIt IMI'.HDDIXU METHODS. 115 



Mitth. Zool. Stat. Ncapel, xii, 1896, p. 353 ; MEYER, ibid., xiv, 1901, p. 

 295 ; MITROPHANOW, Arch. Zool. Expcr. [3], 3, 1896, p. 617 ; FEDERICI, 

 Anat. Anz., xxxi, 1907, p. 602 ; BORDAGE, Bull. Sci. France Belg., xxxix, 

 1905, p. 385; G-ANDOLFI, Zeit. iviss. Mik., xxv, 1909, p. 421; MAYER, 

 ibid., xxiv, 1907, p. 132. 



Other Cold Masses. 



172. Joliet's Gum and Glycerin Method (Arch. Zool. Exper. et 

 Gen., x, 1882, p. xliii). Pure gum arable dissolved in water 

 to the consistency of a thick syrup. Pour a little of the 

 solution into a watch-glass, and add from 6 to 10 drops of 

 pure glycerin. In the winter or in rainy weather less 

 glycerin should be taken than in the summer or dry weather. 



The object is imbedded in the mass in the watch-glass 

 and the whole left to dry for from one to four days. When 

 it has assumed a cartilaginous consistency, a block contain- 

 ing the object is cut out, turned over, and allowed to dry 

 again until wanted for use. A stove, or the sun, may be 

 employed for drying, but it is best to dry slowly at the 

 normal temperature. 



173. STRICKER'S Gum. Method (Hdb. d. Gewebel., p. xxiv). A con- 

 centrated solution of gum arabic. The object is imbedded in the gum 

 in a paper case. The whole is thrown into alcohol, and after two or 

 three days may be cut. The alcohol should be of about 80 per cent. 

 (MAYER). 



I have seen masses of sufficiently good consistency prepared by this 

 simple method. 



174. ROBERTSON'S Grape-sugar Method, see Journ. of Anat. and 

 Physiol., xxiv, 1890, p. 230. 



175. HYATT'S Shellac Method, see Am. M. Mic. Journ., i, 1880, p. 8; 

 Journ. Roy. Mic. Soc., iii, 1880, p. 320. For sections through hard 

 chitinous organs consisting of several pieces, such as stings and ovi- 

 positors, retaining all the parts in their natural positions. 



176. BRUNOTTI'S Cold Gelatin Mass has been given, 155. 



Masses for Grinding Sections* 



177. G. VON Kocn's Copal Method (Zool. Anz., i, 1878, p. 



36). Small pieces of the object are stained in bulk and 



* For the manipulations of section-grinding, see CARPENTER'S The 



Microscope. 



