PREPARING TRICHINELLA SPIRALIS 299 



A METHOD OF PREPARING STUDIES OF 

 TEICHINELLA SPIRALIS OWEN. 



T. T. JOB AND DAYTON STONER. 



This work was first attempted with the idea in mind of 

 securing an adequate supply of laboratory material of 

 Trichinella spiralis for classes in invertebrate Zoology at the 

 State University of Iowa. 



It is the too general belief that such studies are difficult to 

 secure and it is to dispel this idea, in part, that this paper is 

 offered. In fact the comparative ease with which one may 

 secure a presentable series showing the development, growth, 

 migration, encystment, etc., of this worm, affords an unusually 

 good opportunity for illustrating the interesting phenomenon 

 of typical parasitic life. 



Since it is often rather difficult to secure tricliinized meat 

 from the local shops, the material for the following studies 

 was obtained by addressing the Chief of the United States 

 Bureau of Animal Industry at Washington, D. C. This meat 

 contained the worms in the encysted stage and in suitable con- 

 dition for transferring to another host where they might live 

 and reproduce. 



A part of the trichinized pork was fed to four young white 

 rats which were kept confined in a separate cage. After hav- 

 ing eaten of this pork the rats were again given their usual 

 diet. 



THE TRICHINELLAE AND HOST. 



Host No. 1. — Five days after feeding the encysted Trichinella 

 the first subject was killed. Various openings were made at 

 different levels in the stomach and intestine and the digestive 

 content together with scrapings from the mucosa were examined 

 under the dissecting microscope in 5 per cent formalin. 



Free worms were found only in the intestinal content and 

 the mucosa of the upper ileum. Sections of this portion of the 

 intestine were preserved in 10 per cent formalin. 



