THE PARASITES OF THE TERMITES. 441 



ISACIS. 



ISACIS MIGRANS. 



Lespes. Annaies Sci. Nat. Y., 1856, 335. 



In numerous examinations of the parasites of our Termite, always directed to 

 those of the intestines, I but once met with an individual of the thread-worm, 

 which I recognized as the Isacis migrans, discovered by M. Lespes in the Termite 

 of France. While in the act of w^riting the present notice of the worm, I laid 

 down my pen and reflected upon its comparative rarity in our Termite. Recalling 

 to mind the frequent occurrence of a nematoid parasite in the proboscis of the 

 common house-fly, it occurred to me that the Isacis might inhabit the head of 

 the Termite. Having a colony of the latter on my table, I at once took two indi- 

 viduals and examined their heads, and behold in a moment I had displayed 

 beneath the microscope about a dozen individuals of the Isacis. 



In the Termite of France, and likewise in our own, the Isacis occurs in an 

 immature condition; that is to say, without the generative apparatus being devel- 

 oped. In the mature state M. Lespes found the worm in earth of the nest of the 

 Termites, and it is probable that it will be found in the same state under like 

 circumstances with our Termites. 



GREGARINA 



Gregarina termitis. Plate 52, Fig. 2Y. 



A small Gregarina was once noticed in our Termite, and is represented in 

 Fig. 27. The body is ovoid with the narrower end posterior. The head spheroid 

 compressed from above downward. Length 0.06 mm.; head 0.018 mm. long, 0.03 

 broad; body 0.036 mm. broad. 



Of the vegetal parasites found in association with the animal forms, within the 

 small intestine of our Termite, there are two kinds: one a species of vibrio, the 

 other an attached algoid, to which I formerly gave the name of Arthromitus. 



VIBRIO. 



Vibrio termitis. Plate 52, Figs. 36-39. 



Vibrios occur in great numbers as an associate of Trichonymjpha, Pyrso- 

 nympha, and Dinenympha. They resemble most nearly the Vibrio serpens of 

 Miiller, as described by Dujardin, Cohn, and others. Under the highest powers 

 of the microscope at my command, one-tenth objective of Wailes, of Smith and 

 Beck, and No. 11 immersion objective of Hartnack, they appear as immeasur- 

 ably fine lines, usually ranging from 0.03 mm. to 0.045 mm. in length; but in 



84 



