RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 245 



of the insects. It is met with frequently in great numbers ; I have 

 in my collection a vial containing over 5,000, obtained from not more 

 than 40 insects. Sometimes not over half a dozen are found, at 

 others as many as 500 may be discovered in a single insect. The 

 worm is usually curved ventrally, and exhibits but little motion 

 until placed in water, when it becomes quite active, wriggling about 

 for twenty-four hours or more. 



It is about 114 lines long, but varies from i to 2 lines, and is about 

 i-i5oth of an inch wide. The color is white, opaque ; occasionally 

 one or two will be found which are more or less brown or even 

 black, but otherwise they do not differ in construction or form. 



The form is cylindrical, moderately narrowed toward the extremi- 

 ties ; anteriorly truncated, posteriorly rounded, and terminated by a 

 short, acute epidermal spine. 



The structure is simple, exhibiting within the integument nothing 

 but an alimentary canal and intervening granular matter. 



The integument is thin, strong, elastic, transparent and colorless. 

 It presents a very faint appearance of being finely annulated. 



The mouth is round, large, and surrounded by a slight lobed 

 margin or lip. 



The pharynx is short, cylindrical, presents several longitudinal 

 striae, and opens into a long, wide, cylindrical cesophagus. The 

 latter is but faintly outlined from the general granular structure of 

 the body. It appears to have several longitudinal folds, and at its 

 commencement has a yellowish colored structure (pi. 11, fig. 45), 

 apparently corneous, composed of oval or oblong lobes placed side 

 by side around the commencement of the oesophagus. The ven- 

 tricular intestine is white, opaque, cylindrical, a little less than the 

 breadth of the cavity of the body, and in length extending to the 

 anal aperture. Its interior is covered with an epithelial layer, the 

 cells of which are granular, apparently containing oil granules, and 

 measure i -4200th of an inch in diameter. The posterior extremity 

 of the ventriculus is rounded, and usually contains a large oblong, 

 translucent, highly refractive mass, of vicid oleo-albuminoid fluid, 

 with several smaller globular masses of the same matter. When 

 the worm is submitted to pressure, a portion of this matter exudes 

 from the anus, with a number of transparent nucleolar and nuclear 

 bodies, but the termination of the ventriculus, or its connection with 

 the anal aperture, is indistinct. 



The anus is a short oblique fissure, passing inwards and forwards, 

 upon the ventral surface, a short distance in advance of the posterior 

 extremity of the body. It is bounded by projecting lips, but its 



