470 CHAl'TER. XXXVI. 



and stained witli dilute borax-cramiiie. It is important (for 

 preparations that are not destined to be sectioned) to use 

 only dilute borax-carmine, as the strong solution produces 

 an over-stain that cannot easily be reduced. 



Narcotisation by chloral hydrate before fixing is useful, 

 especially for the study of Pentacrinns larvas and of the 

 young Si/naptse formed from Auricularia. Without this 

 precaution you generally get preparations of larvae either 

 shut up (Pentacrinus), or entirely deformed by contraction 

 (young Bynaptm). 



See also MacBeidb on the development of Ainphiura squamaia. 

 Quart. Jouin. Micr. Sci., xxxiv, 1892, p. 131 (osmic acid followed by liquid 

 of Miiller and alcohol ; decalcification with nitric acid in alcohol ; stain- 

 ing with Mayer's paracarmine or hEemalum) ; and Seeligbk on the de- 

 velopment of Autedon, Zool. Jahrb., Abtli. Anat., vi, 1892, p. 161. 



Macbeide (Quart. Juurn. Micr. Sci., xxxviii, 1896, p. 340) fixes larvre 

 of Asterina in osmic acid, Ijriiigs into liquid of Miiller for twelve to four- 

 teen hours, imbeds in celloidin followed by paraflBn (see § 171). and 

 stains sections with carmalum or Delafield's hiEuiatoxylin, best after a 

 foregoing stain of twenty-four hours in borax carmine. 



Mayise {Grnvdziiye, Lee and Maver, 1910, p. 486) arranges 

 a number of fixed and stained Plutei on a sheet of gelatin 

 foil gummed to a slide with enparal, dehydrates by adding 

 alcohol by drops, and adds euparal and a cover. See also 

 Woodland, Quart. Journ. Micr. Sci., xlix, 1905, p. 307. 



Cteltinterata. 



899. Thread-cells.- IwANZOFF {Bidl. Soc. Nut. Urscou, x, 1896, 

 p. 97) advises for the Neniatocysts of Actinia; maceration by the Hert- 

 wig"s method, § 534, or better, fixation for two to five minutes with 

 vapour of osmium followed by a short washing with sea water or distilled 

 water. 



For Medusae he also advises the Hertwig's method, § 534, or treat- 

 ment with a solution containing methyl green and gentian violet with a 

 little osmic acid. 



90O. Little [Journ. App. Mic, vi, 1903, p. 2116; Jvurn. 

 Boy. Mic. Soc, 1903, p. 237) kills Hydra in hot saturated 

 sublimate in 70 per cent, alcohol, washes with alcohol, stains 

 for five minutes in strong solution of methylen blue, dehy- 



