390 EMBRYOLOGY 



and after twenty-four hours therein pierces the membranes and 

 passes through stronger alcohol. 



See also Locy, Bull. Mus. Comp. Zool. Harvard, xii, 3, 1886. 

 Fix by hot water. The liquid of Perenyi may also be used ; it 

 has the advantage of not making the yolk so granular . 



Montgomery {Journ. Morph., xx, 1909, p. 628) fixes ova of 

 Theridiuni for one or two hours in Carnoy and Lebrun's mixture. 



Lambert {ibid., p. 420) fixes ova of Epeira in picro-sulphuric 

 acid warmed to 70° or 80° C. 



PuRCELL {Quart. Journ. Micr. Sci., liv, 1909, p. 7) fixes ova of 

 Atta in boiling saturated sol. of sublimate in alcohol of 70 per 

 cent. 



Hamburger {Zeit. vciss. Zool., xcvi, 1910, p. 3) fixes ova of 

 Argyroneta in Gilson's mixture. 



856. Limulus. Kingsley {Journ. Morph., vii, 1892, p. 38) 

 kills ova by heating in sea-w^ater to 70° or 75° C. and brings into 

 alcohol of 30 to 70 per cent. Similarly Kishinouye, Journ. Coll. 

 Sci. Japan, v, 1892, p. 56. 



857. Decapoda. Reiciienbach {Ahh. Senckenberg Ges. Frank- 

 furt, xiv, 1886, p. 2) fixes ova of Astacus in water gradually 

 warmed to 60° or 70° C. (if the chorion should burst, that is of no 

 consequence), hardens for twenty-four hours in 1 to 2 per cent, 

 bichromate of potash or 0'5 per cent, chromic acid, washes out for 

 the same time in running water, and brings into alcohol. Remove 

 the chorion, and remove the embryo from the yolk with a sharp 

 knife. 



Herrick {Bull. U.S. Fish. Comm., xv, 1896, p. 226) kills the 

 ova in hot water, shells and fixes in picro-sulphuric acid. 



858. For Homarus, see Waite, Bull. Mus. Comp. Zool, xxxv, 

 1899, p. 155. 



859. Amphipoda. Della Valle {Fauna u. Flora Golf. Neapel, 

 XX, Monog, 1893, p. 170) puts ova of Orchestia by means of a 

 pipette into boiling, cold-saturated sublimate solution, removes 

 them instantly into sea-water, and thence into weak alcohol. 

 If the chorion does not burst of itself it must be pricked with a 

 needle. 



860. Cladocera. Haeker {Zellen. u. Befruchtungslehre, 1899, 

 p. 60) fixes females of Sida with winter eggs in a hot mixture of 

 100 c.c. alcohol of 70 per cent, with 1 to 2 c.c. saturated sol. of 

 sublimate. See also Samter, Zeit. wiss. Zool., Ixviii, 1900, p. 176. 



861. Copepoda. Krueger {Atch. Zellforsch., vi, 1911, p. 173) 

 fixes ovaries of Harpactida in Zenker's mixture with 10 per cent, 

 of formol added. No other liquids give good results. 



VERMES 



862. Rotatoria. Jennings {Bull. Mus. Harvard Coll., xxx, 

 1896, p. 101) finds the best fixative for pregnant females is the 



