362 SOME ZOOLOGICAL METHODS. 



720. Sarcolemma of Insecta (THANHOFFER, ibid., 1882, p. 27). 

 In order to demonstrate the two plates of the sarcolemma, 

 digest muscle (of an insect) either in the stomach of a living 

 animal (by wrapping it in gauze and introducing it through 

 a fistula) or in artificial gastric juice (in the former case 

 several hours, in. the latter half to one hour, at the tempe- 

 rature of the room in summer). Examine in gastric juice. 



721. Phalangida (ROSSLER, Zeit. f. wiss. ZooL, xxxvi, 1882, 

 p. 672). The animals are killed in boiling water; the water 

 is allowed to boil up several times, so that the albumen of the 

 tissues may be coagulated ; they are then brought into alcohol, 

 first of 70, then 90 per cent., then absolute, until all water is 

 removed from them. They are then imbedded in soap. The 

 soap is remelted, and allowed to cool once or twice, in order 

 to get the objects thoroughly penetrated. Sections are then 

 made, and stained on the slide with some colouring matter 

 dissolved in absolute alcohol. 



Paraffin was tried for imbedding, but gave no good results, 

 on account of the brittleness of the tissues caused by the 

 preliminary treatment with turpentine or oil of cloves. I 

 fancy that this difficulty would be easily overcome by clearing 

 with cedar oil instead of clove oil, as I have constantly recom- 

 mended for the special purpose of avoiding brittleiiess in 

 tissues. 



722. Macrotoma Plumbea (SOMMER, Inaug. Diss., 1884, p. 4; 

 Zeit. f. wiss. Hik., 1885, p. 234). Fix with boiling water 

 according to the method of Rossler, last , and harden for 

 several hours in picro-sulphuric acid diluted with 5 volumes 

 of water. Wash out with alcohol ; stain with alum- carmine, 

 or Hamann's carmine ( 156), or borax-carmine. Penetrate 

 with chloroform and imbed in paraffin. 



723. Aphid (see ante, 586). 



724. Other Methods for Arthropoda. For Embryological 

 methods, see Chap. XXV, 581 to 593. 



For Spermatological methods, see Chap. XXVI, 612. 



Vermes. 



725. Cestodes. This group must of course be chiefly studied 

 by tin- iiMuil section methods. It is only necessary here to 



