352 CHAPTER XXVI. 



branes can then be removed, and the ova brought for a few 

 hours into absolute alcohol, stained with carmine, and cut. 



628. Blattida (PATTEN, Quart. Journ. Mic. Sci., 1884, p. 

 549). The ova or larvae are placed in cold water, which is 

 gradually raised to 80 C. You leave off heating as soon as 

 the ova have become hard and white. Pass very gradually 

 through successive alcohols, beginning with 20 per cent. 



WHEELER (Journ. of MorpJi., iii, 1889, p. 292; Journ. Roy. 

 Mic. Soc., 1890, p. 250) dissects out ovarian ova in salt solu- 

 tion and fixes in liquid of Perenyi (fifteen minutes), then 

 treats with alcohol, and stains with borax-carmine. Laid 

 eggs may be killed by Patten's method. After heating, the 

 two lips of the crista of the capsule may be separated with 

 fine forceps and pieces of the walls torn away, and the eggs 

 pushed out of the compartments formed by their choria and 

 hardened as desired. Good results are also obtained by 

 heating to 80 C. for ten minutes in liquid of Kleinenberg, 

 and preserving in 70 per cent, alcohol. This causes the en- 

 velopes to dilate and stand off from the surface of the egg, 

 so that they can easily be dissected away. 



HEYMONS (Zeit.f. wiss. ZooL, liii, 1892, p. 434 ; Zeit.f. ii'iss. 

 Nik., ix, 3, 1893, p. 343), for young embryos, incises the 

 cocoon at the end by which it adheres in the body of the 

 mother, brings it for two minutes into water heated to 90 C., 

 and opens in Flemming, in which the embryo is dissected 

 out. 



629. Coleoptera. LECAILLON (Arch. An at. Micr., 1, 1897, 

 p. 208) fixes ova for twenty-four hours in liquid of Zeiiker 

 warmed to 40 C. 



630. Phalangida (HENKING, Zeit.f. wiss. ZooL, xlv, 1886, p. 86 ; Zeit. 

 f.wiss. 3/i/i.,iii, 4, 1886, p. 470). Fix with boiling water or Flemruing. 

 Preserve the ova in 90 per cent, alcohol. To open the chorion, bring them 

 back into 70 per cent, alcohol, which causes them to swell up so that the 

 chorion can easily be pierced with needles, and the ovum turned out. 



631. Araneida. KISHINOUYE (Journ. Coll. Sci. Imp. Univ. 

 Japan, iv, 1891, p. 55 ; Zeit. /. wiss. Mik., ix, 2, 1892, p. 215) 

 fixes in water warmed to 70 or 80 C., puts into 70 per cent, 

 alcohol, and after twenty-four hours therein pierces the mein- 



