ANIMAL PARASITES 101 



ing grades of alcohol, preparations are mordanted in the iron 

 alum for 10 minutes, rinsed in 50 per cent alcohol, and stained 

 for 10 minutes or longer. One hour gives better results for 

 chromatin staining. After staining, decolorize in iron alum and 

 wash in 50 per cent alcohol, or in water, for two hours. 



Reference 



Kofoid, C. A., and Olive Swezy, 1925. Mitosis and multiple fission in 

 trichomonad flagellates. Proc. Am. Acad. Arts Set., 81 (6): 289-378, 

 Fig. 104. 



CESTODA 



Collection. — For obtaining the smaller cestodes Meggitt 

 uses the following technique: 



Open the intestine in lengths of approximately 4 inches, one 

 portion at a time, cut off the part opened and shake vigorously in 

 a flat dish (a convenient size is 10 by 6 by 2.5 inches) filled with 

 tepid water of approximately 40°C. temperature; if the intestinal 

 content be not fresh and consequently contains much mucus, 

 a slightly higher temperature should be employed. Salt solution 

 or cold water should never be used . . . After washing in this 

 manner, the intestine with the attached worms should be removed 

 to another similar dish and examined with a powerful lens, 

 preferably with a binocular, the scolices and smaller worms being 

 dissected out with needles. 



Rapid Examination. — For rapid examination the living scolex 

 may be mounted directly from water into lacto-phenol. 

 Mounted in this way the hooks are clearly visible and can be 

 accurately studied. Meggitt advises ringing the cover slip with 

 a mixture of Canada balsam and hard wax, melted, and applied 

 with a glass rod. 



For more permanent mounts harden the scolex in several 

 changes of 95 per cent alcohol, clear in carbol-xylol, and mount in 

 balsam. 



The hooks of most tapeworms can be isolated in water by 

 teasing the scolex apart under a binocular microscope. With the 

 aid of a small, finely pointed camel's-hair brush touched to 

 Buxton's fluid to make it adhesive the hooks can be transferred 

 directly to a slide and mounted in Buxton's mounting medium 

 (p. 112). 



For the examination of the genital organs staining is necessary. 

 Meggitt, 1924, recommends: 97 parts of a saturated solution of 



