140 RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 



of the body in a looseh' twisted fascicle, are the least active, but 

 at times stretch outwardly and become more divergent at the ends, 

 or they become more closely applied to the sides of the body. When 

 the head is bent to one or the other side, with the summit directed 

 forward, it gives rise to an appearance resembling the spiral peri- 

 stome of a Stcntor. Viewed on end, the parasite appears circular 

 with long divergent cilia, and reminds one of the upper view of a 

 I'orticella. 



2. Pyrsotiympha Vcrtens. The two remaining animal parasites 

 are Infusoria. The larger of the two is often more abundant than 

 the Trichonympha, and is about the i -200th of an inch in length. 

 It is more delicate, less distinctly defined, and undergoes rapid dis- 

 solution after removal from the intestine of the Termite. It is elon- 

 gated fusiform, or, when shortened, clavate or pyriform in outline. 

 Like Tricho)Lymplia, it usually remains stationary in position, while 

 actively moving, writhing, apparently twisting, and often bending 

 in a waving manner from one extremity to the other. In motion, 

 longitudinally spiral and parallel lines become more or less evident 

 and frequently cause serrated projections at the extremities or at 

 the prominence of the bends when produced at the lateral borders. 

 These exhibit a rapid waving motion, strikingly resembling the 

 movement of flames and probably denoting the presence of minute 

 cilia, though these were not positively seen. A narrow band ex- 

 tends the length of the body, sometimes projecting at one end, and 

 moves in long angular waves, flexing the body in accordance with 

 its movement. The body appears to be composed of finely granular 

 protoplasm, with but faint distinction of endo and ectosare. A 

 large oval or round granular nucleus occupies a position in advance 

 of the middle of the body. The position of the mouth was not de- 

 tected, though one is most probably present, as the animalcule is 

 often replete with large particles of food, consisting of bits of wood. 

 Pyrsonympha may be the larval condition of Trichony»ipha, though 

 there is no evidence that such is the case. 



3. Ditienympha Gracilis. A Ciliate Infusorian, the smallest and 

 most abundant of the three animal parasites, about i -350th of an 

 inch in length, is flattened, fusiform, and in motion often twisted. 

 It is longitudinally and, in the twisted condition, spirally striated, 

 and is invested everywhere with fine cilia. The animal usually, re- 

 maining like its companions nearly stationary in position, writhes 

 from side to side, shortens and widens, or lengthens and contracts, 

 and rotates in the long axis. The longitudinal lines of the bod}^ by 

 contraction produce a serrated appearance at one end, or at the 



