CHAPTER XXXVI. 519 



Spicula and the skeleton of pedicellarise may be cleaned by eau de 

 Javelle, see DODERLEIN (Wiss. Ergeb. Tiefsee-Eioped., v, 1906, p. 67). 



972. Asteroidea. HAMANN (Beitr. Hist. Echinodermen, ii, 1885, 

 p. 2) injects the living animal with a fixing liquid through the tip 

 of a ray. The ambulacral feet and the branchiae are soon distended 

 by the fluid, and the animal is then thrown into a quantity of the 

 same reagent. 



In order to study the eyes, with the pigment preserved in situ, 

 they should be removed by dissection, should be hardened in a 

 mixture of equal parts of 1 per cent, osmic acid and 1 per cent, 

 acetic acid, and sectioned in a glycerin gum mass, or some other mass 

 that does not necessitate treatment with alcohol (which dissolves 

 out the pigment, leaving the pigmented cells perfectly hyaline). 

 For maceration use one-third alcohol, the aceto-osmic mixture 

 failing to preserve the rods of the pigmented cells. 



Specimens for externals only preserve in 70 per cent, -alcohol or 

 formalin. They retain their shape better if they are put for two or 

 three minutes into fresh water before being placed in the fixer. 

 If the internal anatomy is to be studied, cut along the length of each 

 arm so as to allow fluid to enter, and preserve in 2 per cent, chromic 

 acid, etc. Wash in running water, transfer to 70 per cent, alcohol ; 

 or the specimen may be preserved in formalin spirit or 5 per cent. 

 formalin. 



Formaldehyde is not to be recommended for the cell preservation 

 of Asteroidea (WEBER). See also *Lo BIANCO, op. cit. (he kills 

 Brisinga with absolute alcohol), also 17, 20. 



973. Ophiuridea should in general be killed in fresh water if it 

 be desired to avoid rupture of the rays (DE CASTELLARNAU, La 

 Est. Zool. du Napoles, p. 135). 



Lo BIANCO kills small forms with weak alcohol, Ophiopsila with 

 absolute alcohol, and Ophiomyxa with -5 per cent, chromic acid. 



Russo (Richerche Lab. Anat. Roma, iv, 1895, p. 157) fixes 

 Ophiothrix for an hour or two in 0-5 per cent, osmic acid and then 

 decalcifies in solution of Muller for six to ten days. Or he fixes for 

 three minutes in a mixture of 2 parts concentrated sublimate 

 solution, 1 part 70 per cent, alcohol, and 1 part acetic acid (sp. gr. 

 1-06), and decalcifies in Muller or in 70 per cent, alcohol with 10 

 per cent, of acetic acid. He stains with paracarmine. 



974. Crinoidea. Lo BIANCO (loc. cit., p. 458) fixes Antedon 

 rosacea with 70 per cent, alcohol, A. phalangium with 90 per cent. 



