TUKBELLAEIA. 363 



remind the reader that, as pointed out by VOGT and YUNG 

 (Trait. d'Anat. Comp. prat., p. 204), the observation of the 

 living animal may be of service, especially in the study of the 

 excretory system. And, as shown by PINTNER, taeniae may be 

 preserved alive for several days in common water to which a 

 little white of egg has been added. 



726. Trematodes (FISCHER, Zeit. f. iviss. ZooL, 1884, p. 1). 

 Opisthotrema cochleare may be mounted entire in balsam, after 

 treatment with absolute alcohol, picro-carmine, or haema- 

 toxylin or ammonia-carmine, and clearing with clove oil. 

 For sectioning, Fischer recommends imbedding in a mass 

 made by dissolving 15 parts of soap in 17*5 parts of 96 per 

 cent, alcohol. This mass melts at about 60 C., penetrates 

 very rapidly, and solidifies very quickly. The sections should 

 be studied in glycerin. 



WRIGHT and MACALLUM (Journ. of Morph., i, 1887, p. 1) find 

 thai Sphyranura is for most purposes best fixed in liquid of 

 Flernming, and stained with alum cochineal. 



Cercarise. SCHWARZE (Zeit.f. wiss. Zool., xliii, 1886, p. 45) 

 found that the only fixing agent that would preserve the histo- 

 logical detail of these forms was cold- saturated sublimate 

 solution warmed to 35 to 40 C. 



727. Turbellaria. For Rhabdoccela BRAUN (Zeit. f. iviss. 

 Mil:., iii, 1886, p. 398) proceeds as follows : For preparing 

 entire animals the animals are got qn to a slide, lightly flat- 

 tened out with a cover, and killed by running under the cover 

 a mixture of three parts of liquid of Lang with 1 per cent, 

 osmic acid solution. After due fixation therein, they are 

 tmited for some time with successive alcohols, the cover is 

 removed, the objects are stained with alum-carmine (two to 

 three minutes is enough), washed, and brought into balsam 

 in the usual way. Other fixing media than that described 

 were not satisfactory. (BOHMIG, however, commenting on 

 this, says that for some of the tissues, such as muscle and 

 body parenchyma, nitric acid and picro-sulphuric acid are 

 very useful.) Sections may be made by the usual paraffin 

 method. 



DELAGE (Arch, de Zool.exp. et gen.,iv, 2, 1886; Zeit.f. wiss. 

 .Wik., iii, 2, 1886, p. 239) strongly recommends fixation (of 

 Rhabdoccela) by the osmium-carmine mixture, 161. Con- 



