4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. C8 



Ectohia gei^nianica). On October 6 the culture was found to be 

 covered with a heavy mold but the e<>:gs were apparently unharmed 

 as no change was apparent in them. The culture was divided into 

 8 parts and to these were added the following, respectively : char- 

 coal, a little j)otassium bichromate and about 2 per cent formalin. 

 The roaches were fed from these cultures at irregular intervals dur- 

 ing the month of October. 



On October 26 one roach was found dead. Upon dissection nu- 

 merous larvae of various sizes were found free in the body cavity; 

 none could be found to have encysted. The larvae (apparently sec- 

 ond stage) measured 90/* to 1.1 mm. long; the tail end was devoid 

 of spinous processes. 



On November 3 the dissection of a second roach, found dead on 

 that day, revealed a large number of spirurid larvae, in the loose 

 tissue of the body cavity, especially in that around the tracheal tubes. 

 Many of the larvae were coiled in a tight spiral and exhibited very 

 sluggish movement; several were in loose cysts. The larvae (ap- 

 parently third stage) measured 1.1 to 1.2 mm. long by 50/x wide; 

 first part of esophagus 6G/J, long, second part of esophagus 440/a long, 

 anus 75/t from tail end. In lateral view the end of the tail showed 4 

 spinous processes, the 2 median being larger than the 2 outer. About 

 10 larvae were fed to a white mouse and about 20 to a white rat. 

 The mouse died on November 17 but no spirurids were found in the 

 stomach or esophagus; the rat was killed on December 27 and the 

 findings in regard to it were also negative. 



On November 13 a roach which was killed and dissected, was 

 found to have 19 encysted larvae in the abdominal cavity. Six of the 

 larvae were fed to a white mouse which died on November 15 with 

 evidences of hemorrhage, there being blood at the mouth and blood 

 clots in the stomach. One spirurid larva was found in the stomach ; 

 it was of about the same size (1.2 mm. by SOj;.) as the encysted ones 

 which had been fed. 



On December 1 a roach which was killed and dissected was found 

 to contain numerous encysted larvae in the abdominal and thoracic 

 cavities, the cysts being loose among the tissues around the mouth 

 parts, in the fleshy coxa of the legs, and among the salivary glands 

 and the Malpighian tubes. Forty-three cysts were collected, a few 

 of them containing 2 larvae but the great majority only one. The 

 cysts measured about 425 to 440[;, in diameter; the larvae were the 

 same size (1.2 mm. by 50;j.) as those collected from roaches previously 

 examined. A white mouse was fed 8 cysts, and 2 white rats 12 cysts 

 apiece. The mouse died on December 15 but no spirurids could be 

 found in the esophagus or stomach. One of the rats was killed on 

 January 5 and 4 imnuiture specimens of /^ columbiana found in the 

 stomach, 3 males (17 to 20 mm. long by 450 to 500ix wide) and 1 



