430 THE PARASITES OF THE TERMITES. 



becomes somewhat elongated and narrower, and its summit more protuberant, and 

 by contraction becomes in a corresponding degree shortened, widened, and more 

 blunt. Often also the head turns backward, then forward. The body elongates 

 and becomes narrowed, regularly tapering, and more or less pointed, rounded, or 

 abruptly truncated; or it contracts and becomes shorter and oval, or abruptly 

 bulges where it joins the head, and narrows abruptly towards the extremity; and 

 sometimes it makes a half twist, or swells on one side and becomes depressed on 

 the other. Frequently the head and body shorten and widen together, and the 

 former sinks more or less deeply into the latter, as represented in Figs. 1 to 3. 



Viewed on end Trichonympha appears circular, as seen in Fig. 4, inclosino- 

 a pair of inner circles produced by the outline of the head and a nucleus within. 



The interior of Trichonympha is occupied by a mass nearly conforming in 

 shape with the exterior, and like this consists of two corresponding portions. 

 These would appear to relate to the two portions of the granular endosarc in a 

 gregarine; and they have reminded me, at least in relative position and volume, 

 with the capacious pharynx and stomach of a turbellarian worm. 



As for convenience I have considered the two parts of the animal as head 

 and body, for the same reason I shall speak of the outer and inner structures 

 as ectosarc and endosarc, without regarding them actually as such in relation with 

 an infusorian or other protozoan. 



The anterior division of the endosarc occupies about three-fourths of the 

 capacity of the head, appearing to be inclosed in a thick wall of ectosarc. It 

 would seem to be conical, with the apex acuminate and the base abruptly termi- 

 nating in the body endosarc on the line of conjunction of the head and body of 

 the animal, as seen in Figs, 5-7, 9, 10. More closely examined, the head endo- 

 sarc would appear to be ovoid, with the posterior broader extremity received into 

 a depression of the body endosarc, as represented in Figs. 1-3, 8. The anterior 

 acuminate end is extended to a point at the summit of the head. 



The head endosarc is homogeneous, or very minutely and uniformly granular 

 throughout. Its structure appears consistent and not fluent, or even semifluent 

 as in the endosarc of gregarines and infusorians, but it presents no trace of 

 striation or fibrillation to distinguish it as probably being of muscular nature. It 

 is, however, elastic, and elongates and contracts in correspondence with movements 

 of the head. 



The body endosarc occupies a greater proportion of the interior capacity of 

 the body than that of the head, but is less well defined from the inclosing ecto- 

 sarc, especially at the posterior part, where it often appears insensibly to gradate 



