c(,A Journal of Agricultural Research . voi. iv. No. 6 



female has a flattish, hemispherical lip region, set off by a more or less 

 distinct constriction. The striae begin to diminish in size in the neigh- 

 borhood of the base of the spear, and are only about one-third to one-half 

 as wide at the base of the lips as they are farther back. These transverse 

 striae are so pronounced a feature that they give to the contour of the 

 body a crenate appearance, especially toward the posterior extremity. 

 The lip region also is minutely transversely striated, the number of 

 labial striae being about 8 to lo. There are arched radial ceratinous 

 elements in the lip region, but these have not been accurately counted. 

 It seems likely there are about six of them. The mouth opening is very 

 small, and the vestibule is strengthened by ceratinous elements which 

 serv^e as a guide to the spear. This latter is somewhat longer than the 

 base of the head is wide and in the females at least is a strongly developed 

 and doubtless very efficient organ. It may be divided into two regions 

 the posterior of which is cylindrical, and ends at its hinder extremity 

 in a strongly developed threefold bulb, about one-fourth as wide as the 

 corresponding portion of the head, and to which are attached muscles 

 that pass forward to near the outer portion of the base of the Up region. 

 The anterior half of the spear is narrower, ends anteriorly in a somewhat 

 blunt point, and is hardly half as wide as the larger posterior cylindrical 

 portion. At the base of the spear the oesophageal tube begins. At this 

 point it is about two-fifths to one-half the width of the corresponding 

 portion of the neck. It has this diameter until near the median bulb, 

 where it diminishes in such a way that at the actual junction with the 

 bulb the diameter of the definite constriction separating it from the 

 bulb is only one-fourth to one-sixth that of the neck. The median bulb is 

 fairly well developed in the female, though much deteriorated in the male. 

 In the female it is elongated to ellipsoidal in form, and about two-thirds 

 as wide as the corresponding portion of the neck. It is supplied with a 

 fairly well-developed but somewhat simple refractive valvular apparatus 

 having a diameter nearly one-third as great as that of the bulb itself. 

 Behind the bulb the oesophagus is again narrow — about one-sixth as wide 

 as the corresponding portion of the neck. It soon widens out a little 

 so as to become more than half as wide as the base of the neck. It joins 

 the intestine in a somewhat indefinite manner. The length of the pos- 

 terior part of the oesophagus may be judged by the fact that the distance 

 from the anterior margin of the median bulb to the end of the oesophagus 

 equals nearly half the length of the neck. In stained specimens the 

 beginning of the intestine is indicated by the special cardiac cells of the 

 intestine, which stain more strongly than the cells immediately behind 

 them (fig. i). The intestine is made up of cells which are packed with 

 spherical granules of various sizes and of more than one kind. The 

 smallest of the granules of the smaller sort have a diameter considerably 

 less than the width of one of the striae; the larger are two or three times 

 as wide. The fatty granules or accretions of the intestine, the granules 



