216 Animal Micrology 



Opalina may be obtained readily by killing a frog wich chlo- 

 roform and slitting open the large intestine. Examine scrapings 

 of the epithelial wall in normal saline (reagent 74, Appendix B). 



Sporozoa. Gaegarina may be found in the alimentary canal of 

 the cockroach and Monocystis, in the male reproductive organs of 

 the earthworm. They are best studied in normal saline. If it is 

 desired to stain and mount specimens they may be fixed in corro- 

 sive-acetic (reagent 14, Appendix B) for 5 minutes, washed thor- 

 oughly in 35 per cent, alcohol to which a little tincture of iodine 

 has been added, and stained with Ehrlich's triple stain (reagent 

 39), or hematoxylin and acid fuchsin (reagents 49 and 42). 



b) Quieting infusoria. 1. Let sufficient water evaporate from 

 under the cover to permit the latter to press lightly upon the ani- 

 mals. Guard against too great evaporation of water or the infu- 

 soria will be crushed. 



2. Entanglement in fibers of cotton, etc., sometimes proves 

 efficacious. 



3. A small amount of gelatin or better, cherry-tree gum, dis- 

 solved in water makes a viscous mass which is often useful in 

 retarding their motions. A bit of white of egg may be used in 

 the same way. 



4. Animals may be narcotized by means of a small drop of 

 very dilute alcohol (preferably methyl alcohol) or chloretone 

 (about one drop of a 1 per cent, solution to 10 drops of water). 

 (Chloretone is manufactured by Park, Davis & Co., of Detroit, 

 Mich. For its use as an anaesthetic in biological work see Jour- 

 nal of Applied Microscopy, Vol. V, p, 2051.) 



c) Feeding. Place finely pulverized carmine or indigo under 

 the cover-glass. The colored powder rapidly accumulates in the 

 food vacuoles. In such a preparation the action of the cilia of 

 infusoria is also indicated by the rapid movement of the particles 

 in the vicinity of the animal. See also chap, xiv, memorandum 4. 



d) Staining. For intra vitam staining see Appendix B, rea- 

 gents 55a, 31, and 58. 



To see cilia of infusoria treat the animal with very dilute 

 iodine solution or a drop of a dilute solution of tannin. 



