II. A FAUNA WITHIN ANIMALS. 41 



CHAPTER II. 



A FAUNA WITHIN ANIMALS; BEING DESCRIPTIONS OF NEMATOID ENTOZOA FOUND 

 ASSOCIATED WITH ENTOPHYTA, AND OF OTHERS ALLIED TO THEM. 



ASSOCIATED with the extraordinary flora of the intestinal canal of Julus margina- 

 tus and Passalus cornutus, there is also a rich fauna. Within the former animal, 

 there exist, with a good deal of constancy, the following entozoa : 



1, Gregarina Juli marginati, 1 within the proventriculus; 2, Ascaris infecta ; 3, 

 Streplostomum agile; 4, TJielastomum attenuatum ; 5, Nyctotlierus velox / 6, Bodo 

 julidis; 3 and 7, a species of Vibrio, within the ventriculus and large intestine. 



In Passalus cornutus are found : 



1, Gregarimi Passali cornuti* within the proventriculus ; 2, Hystrignathus rigidus, 

 within the ventriculus. 



External to the intestinal canal, and within the abdominal cavity, there is like- 

 wise found an enormous quantity of a species of nematoid worm, apparently not 

 fully developed, 5 and in the thoracic cavity a second species is occasionally observed. 8 



The only helminth observed in the intestinal canal of Julus pusillus was a spe- 

 cies of Gregarina} 



The common cockroach, Blatta orientalis, contains within its intestinal canal 

 several species of animals, frequently in great numbers, and also, according to 

 Valentin, 8 an entophyte which grows from the mucous membrane of the large in- 

 testine. The same plant, Valentin states, grows within the rectum of Astacus 

 fluviatilis. He refers it to the genus Hygrocrocis, under the specific name of H. in- 

 testinalis, and thus characterizes it: " Fila simplicia, tenuissima, prolonga, articulata, 

 serpentina, apice recta, moniliformia, articulis globosis." 



A plant agreeing with this description I have not been able to find in the same 

 insect, the cockroach, introduced into this country ; but, instead of it, in the same 

 situation mixed with the contents of the intestine, or growing from its mucous 

 membrane, or occasionally from the nematoidea infesting the cavity, simple, 

 inarticulate, amorphous filaments from the ^onr to the ^o^^ of an inch in dia- 

 meter (PL VII. l,e). 



The entozoa of Blatta orientalis are : 1, Vibrio ; 2, Bodo; 3, Nyctotlierus ovalis ; 9 

 4, Gregarina; 10 5, Streptostomum gracile; and 6, Thelastomum appendicufatum. 



1 Trans. Am. Phil. Soc., x. 237. 3 Ib. x. 244. 3 Ib. 4 Ib. x. 238. 5 Ib. x. 241. " Ib. 243. 7 Ib. 238. 

 8 JRepert. fur Anat. und Phys., Band 1, S. 110, 1836. Robin : Des Ytgit. qui crois. tur L'Homme, 

 etc., p. 82, 1847. " Trans. Am. Phil. Soc., x. 244. Ib. x. 239. 



