SOME METHODS FOE LOWER ANIMALS. 467 



by Looss, for making chitin transparent and permeable to 

 reagents, has been described, 556. 



LIST (Zeit. f. wiss. Mik., 1886, p. 212) has obtained good 

 results with Coccidae by treating them (after hardening) for 

 eighteen to twenty-four hours with eau de Javelle, diluted 

 with four volumes of water. After washing out with water, 

 they may be dehydrated with alcohol and imbedded in 

 paraffin, the chitin being sufficiently softened to allow of their 

 being penetrated and good sections being obtained. You 

 may stain before imbedding, with alum-carmine or picro- 

 carmine (five to six days). 



SAZEPJN'S method for antennae of Chilognatha (Mem. Acad. 

 Imp. St. Pe'tersb., xxxii, 9, 1884, pp. 11, 12) consists in 

 steeping antennae (that have been dehydrated with alcohol) 

 for twenty-four hours in chloroform containing a drop of 

 fuming nitric acid (shake occasionally). 



See also the depigmentation. processes, 575 to 582, and 

 BETHE'S method, 843. 



838. Eyes of Arthropods. For the methods of LANKESTEK 

 and BOURNE (Quart. Journ. Mic Sci., 1883, p. 180 : Limulus) ; 

 HICKSON (ibid., 1885, p. 243 : Musca) ; PARKER (Bull. Mus. 

 Harvard Coll., xx, 1890, p. 1; Zeit. f. wise. Milt., viii, 1891, 

 p. 82 : Homarus) see previoiis editions. 



In a later paper (Mitth. Zool. Stat. Neapel, xii, 1895, p. 1 ; 

 Zeit. f. iviss. Mik., xii, 4, 1896, p. 496) PARKER describes the 

 application of the methylen blue method to the study of the 

 retina and optic ganglia in Decapods, especially in Astacus. 

 He injected 0*1 c.c. of a 0'2 per cent, solution into the 

 ventral sinus. After twelve to fifteen hours the animals 

 were killed, the ganglia quickly dissected out, and the stain 

 fixed as described, 329. 



For his method for eyes of Scorpions see 582. 



For the methods of PDRCELL for the eyes of Phalangida 

 see Zeit. f. wiss. Zool., Iviii, 1894, p. 1; Zeit. f. wise. Mik., 

 xii, 1, 1895, p. 44. He has the following stain. The 

 cephalothorax is removed and brought for twenty minutes 

 into 50 per cent, alcohol warmed to 45 or 50 C., and 

 saturated with picric acid. The pigment dissolves in this 

 solution and stains the nuclei and some other parts of the 

 rhabdoms, so that no further stain is required. 



