3 00 IOWA ACADEMY OF SCIENCE 



Host No. 2. — Nine days after feeding, a second subject was 

 killed. The procedure was as in No. 1. In addition, an ex- 

 amination of several blood smears from the superior mesenteric 

 vein and the heart was made. Only one young Triehinella 

 was found in the smears and that in the blood from the heart. 

 The embryos at this stage were developed to such an extent 

 that they could readily be seen in the body cavity of the female. 



Again sections of the upper ileum were preserved in 10 per 

 cent formalin. 



Host No. 3. — Fourteen days after feeding, the third subject 

 was killed. The method was as above. Blood smears were neg- 

 ative. The Triehinella? were found a little further down in 

 the ileum and were much larger than in the nine day stage. 



Host No. 4. — The fourth subject was to have been killed 

 twenty-one days after feeding, but it died of trichinosus on the 

 night of the twentieth day. 



On examination, free intestinal Triehinella? were found in 

 the middle ileum. The muscles surrounding the abdominal cav- 

 ity, diaphragm, internal and external oblique, transversalis and 

 Pvsoas, as well as the extensor muscles of the hind legs showed 

 Triehinella? in the migratory and resting stages. A considerable 

 number were found in these muscles but the masseter muscles 

 showed the various stages even better and more abundantly. 



In this stage the entire body of the host was preserved in 10 

 per cent formalin. 



METHOD OF PREPARATION. 



The material was handled in watch glasses with pipettes. 

 First, the preserved material was washed thoroughly with dis- 

 tilled water. This not only removes the formalin but separates 

 the Triehinella? from the other material so that the worms may 

 be collected in a pipette and transferred to the next dish. The 

 staining and dehydration were carried on in the same dish so 

 as not to injure or lose the specimens, the different fluids being 

 added and drawn off with the pipette. 



Killing and Fixing. — Ten per cent formalin was used in all 

 cases to kill and fix the tissues and Triehinella?. Carnoy's so- 

 lution may be used with equally good results. 



Staining. — Delafield's hematoxylin and erythrosin, orange G. 

 methyl green, borax carmine and iron hematoxylin (Heiden- 



