464 CHAPTER XXXVI. 



macerating for one or two days in 2 per cent, acetic acid, staining with 

 aceto-carmine, and teasing. 



889. Nemertina. My best results have always 

 obtained by fixing with cold saturated sublimate solution, 

 acidified with acetic acid. The other usual fixing agents, 

 such as the osmic and chromic mixtures, seem to act as irri- 

 tants, and provoke such violent muscular contractions that the 

 whole of the tissues are crushed out of shape by them. 



Prof. DU PLKSSIS has suggested to me fixing with hot 

 (almost boiling) water. I have tried it and found the 

 animals die in extension, without vomiting their proboscis. 

 So also JOUBIN, Bull. Hits. Hist. Nat., 1905, p. 326. 



I have tried FOETTINGKK'S chloral hydrate method ( 20). 

 My specimens died fairly extended, but vomited their pro- 

 boscides. According to Lo BIANCO narcotisation with a 

 solution of O'l to 0'2 per cent, in sea water for six to twrlve 

 hours is useful. 



OESTEUGREN ( 18) recommends his ether water. 



DENDY (see Journ. Roy. Mic. Soc. } 1893, p. 116) lias 

 succeeded with Geonemertes by exposing it for half a minute 

 to the vapour of chloroform. 



For staining fixed specimens in toto I have found that it 

 is well-nigh necessary to employ alcoholic stains. Borax- 

 carmine or Mayer's alcoholic carmine may be recommended ; 

 not so cochineal or hsematoxylin stains, on account of the 

 energy with which they are held by the mucin in the skin. 



Sections by the paraffin method, after penetration with 

 oil of cedar (chloroform will fail to penetrate sometimes after 

 a lapse of weeks). 



BURGER (Fauna u. Flora Golf. Neapd, xxii, 1895, p. 443) 

 studies the nervous system, nephridia, skin, muscle and 

 intestine by the intra vitam methylen-blue method. He 

 injects the animals with 0'5 per cent, solution in distilled 

 water, or 0'5 per cent, salt water, and allows them to lie for 

 dix to twelve hours or more in moist blotting paper. 



See also MONTGOMERY (Zool. Jahrb., Abtli. Morph., x, 1897, p. 6) ; and 

 BOHMIG (Zdt. wiss. Zool, Ixiv, 1898, p, 484). 



890. Cestodes. As pointed out by VOGT and YUNG (Trait*' 

 d'Anat. Comp. Prat., p. 204), the observation of the living 



