32 2 ORDER FLAGELLATA-PANTOSTOMATA. 



with younger individuals. This sUght disparity of contour, BiitschU suggests, may 

 be possibly accounted for by the fact that Stein turned his examples into pure water, 

 a medium which, proving uncongenial to their habits, may have resulted in their 

 . assumption of a more contracted shape. Using himself a solution of the white of 

 Qgg, he preserved the animalcules in a healthy and normal state for a space of 

 twenty-four hours and upwards. The presence of food-particles within the sub- 

 stance of the endoplasm has been observed by both of the authorities quoted, Stein 

 further reporting the possession of a narrow, crescentic oral aperture at the anterior 

 extremity. The existence of such a structure is, however, not confirmed by the 

 investigation of Butschli. The food-particles ingested are usually collected together 

 in the posterior half of the body, leaving the anterior moiety clear and transparent ; 

 the expulsion of effete matter at the posterior extremity was on one occasion wit- 

 nessed by Butschli. Not unfrequently this investigator observed that the body- 

 plasma of the posterior end was drawn out in a tail-like manner ; his illustration 

 given of this phenomenon being at the same time connected with one of the rounder 

 or younger individuals, would seem to indicate that in this earlier stage the sarcode 

 of the body presents that greater amount of viscosity or ductility which is common to 

 the young, and in some instances to the adults also, of the more simple monadine 

 types. The first step towards the process of increase by fission has been observed, 

 but not the complete act. In one of these suspected instances there was an appear- 

 ance as of fine cilia at the posterior extremity of the body. The movements of the 

 flagella-fascicle of this animalcule are somewhat complex, the central bundle of 

 straight and longer ones undulating together rhythmically, while the shorter and 

 reflected lateral ones vibrate independently. 



Lophomonas striata, Butschli. Pl. XIX. Fig. 51. 



Body variable in shape, mostly subfusiform, v^ith an attenuate and 

 pointed posterior extremity, but sometimes ovate and rounded in this 

 region ; anterior border abruptly and somewhat obliquely truncate ; 

 flagella-fascicle brush-like, similar to that of L. blattarum, but somewhat 

 shorter in proportion to the length of the body ; the entire external surface 

 distinctly and obliquely striate ; contractile vesicle and endoplast not 

 yet observed. Length 1-800". 



Hab. — Intestine oi Blatta {Periplaiietd) orientalis. 



Although the characters of this animalcule appear sufificiently distinct for separate 

 specific recognition, Butschli entertains some doubt whether it may not ultimately 

 be found to represent a transitional condition only of Z. blattariim. The two, 

 while tenanting the same specific host, were, however, usually found inhabiting 

 separate individuals, and did the present form represent a developmental phase only 

 of the other, it would scarcely have escaped Stein's notice. The substance of the 

 parenchyma in this type or variety would appear to be much more homogeneous than 

 in the form last described, A clear vacuolar space was on one occasion noticed near 

 the anterior extremity, but no trace of an endoplast or nucleus could be detected. 



Leydig has briefiy referred, in his anatomical description of the mole-cricket, 

 Gryllotalpa, to a globose animalcule bearing a lateral tuft of undulating hairs, that 

 inhabits the intestinal tract of that insect. As remarked by Butschli, it is highly 

 probable that this organism represents another species of Lophomonas^ as also 

 that this genus has numerous other representatives distributed among the Ortho- 

 pterous order of the Insecta. 



Fam. XVIII. CATALLACTID.^, S. K. 



Animalcules coherent in social clusters, their anterior and exposed 

 border clothed with long vibratile flagella ; no distinct oral aperture. 



