1 68 Phylum N emathelminthes 



the petri dish. The infective larvae migrating from the culture over the 

 agar cause their trails to be inoculated with bacteria. By the growth of 

 these the courses taken by the worms are readily observed. 



Bibliography 



Cort, W. W., Stoll, N., and Grant, J. B. 1926. Amer. J. Hyg. Monog. Ser. 



7:19. 

 Darling, S. T. 1911. Strongyloides infections in man and animals in the 



Isthmian Canal Zone. J. Exper. Med. 14:1. 

 Dove, W. E. 1932. Further studies on Ancylostoma braziliense and the etiology 



of creeping eruption. Amer. J. Hyg. 15:664. 

 Fulleborn, F. 192 1. Nachweis von Ankylostomum durch Plattenkot-cultur. 



Vorl. Mifteilg. Arch. f. Schiffs und Tropenhyg. pp. 121-123. 

 Looss, A. 1911. The anatomy and life-history of Anchylostoma duodenale Dub. 



Reeds, of Egypt Govt. Sch. of Med., Cairo, IV. 

 White, G. F. 1927. A method for obtaining infective nematode larvae from 



cultures. Science 66:302. 

 White, G. F., and Dove, W. E. 1928. The causation of creeping eruption. 



J . A.M. A. 90:1701. 

 1929. A dermatitis caused by larvae of Ancylostoma caninum. Arch. 



Dermal, and Syph. 20:191. 



Order hologonia, Family trichinellidae 



REARING TRICHINELLA SPIRALIS 



Reed O. Christenson, University of Minnesota 



THE difficulty of isolating developmental stages of Trichinella spiralis 

 has restricted its laboratory use often to mere demonstration of the 

 cysts and, more rarely, the adults. It is feasible, however, with a little 

 experience to have on hand for laboratory use ample material of all stages 

 of the parasite in the living condition. The main difficulty lies in ob- 

 taining the original infection. Usually a routine examination of wild 

 rats about abattoirs or packing houses will yield material. If this source 

 fails, infected animals may often be obtained from other laboratories. 



When trichinosed tissue is obtained a number of animals should be fed 

 to maintain a supply. Rats are ideal, but guinea pigs and rabbits may be 

 used with good results. Cats are more difficult to handle but are ideal 

 animals in which to maintain the infection over long periods of time. 



Shortly after the ingestion of infective meat the larvae are liberated 

 from their cysts by the action of the digestive juices. This may be done 

 experimentally by placing infected tissue in an artificial gastric juice com- 

 posed of water, 1,000 cc; hydrochloric acid, 10 cc; scale pepsin 

 (U. S. P.), 2.5 grams; and sodium chloride, 5.0 grams. Small quantities 

 of finely cut meat are stirred up in the mixture and incubated at 38 ° to 

 40 C. for 18 hours. 



