276 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



the testicle has been forced out of the body of the worm, a large, abrupt 

 expansion of the tube l mm (.04 inch) from its inferior termination. 

 This bag-pipe-like enlargement gradually contracts anteriorly and con- 

 tinues as a cylindrical tube slightly narrower than at its commencement. 

 At the middle of the worm's body it twines about the intestine, then re- 

 descends and terminates in a cul-de-sac near the posterior extremity. 

 The disposition of this seminiferous tube may be better seen when, by 

 a fortunate compression, or a patient dissection, it has been forced out 

 of the body. The three portions of which it is composed may then be 

 readily distinguished: the first as a vas deferens, the second as a vesi- 

 cula seminalis, and the third (which coils about the intestine) as the tes- 

 ticle proper. The latter is filled with an opaque, amorphous substance, 

 the contents of the vesicula seminalis and the vas deferens being likewise 

 opaque but segmented into granular corpuscles of very varying forms, 

 having each a nucleus of .01 to .03 mm (.0004 — .0012 inch) in diame- 

 ter. These are the spermatozoids. The vas deferens, about ,075 mm 

 (.003 inch) in diameter, opens at the posterior extremity of the body 

 in the center of the caudal bursa, between two very small, short, and 

 nearly straight spicules, the extremities of which rest immovably in the 

 vagina of the female. The vesicula seminalis, enlarged in the form of 

 a pear, has its walls made up of muscular fibers which are all obliquely 

 placed and inserted into a longitudinal raphe" like the barbs of a feather 

 into the shaft. The object of this arrangement undoubtedly is to cause 

 the expulsion of the spermatozoids and their projection into the vagina 

 of the female, the long duration of this function requiring a special and 

 powerful apparatus. 



Female genital apparatus (Plate II, Fig. 6). — As in almost all nema- 

 todes, the female generative organs comprise a uterus with two long 

 branches narrowing abruptly into a tubular portion, the ovary proper. 

 We have not been able to discover a bag-pipe-like swelling near the 

 commencement of the ovary which E. Perrier has seen in the Eedruris 

 armata, and which he calls the copulation pouch (vesicula copulatrix). 

 Neither this pouch nor anything similar to it exists in the syngame. 



The vulva, as has been stated, is a small opening pierced through the 

 summit of a hemispherical papilla which is permanently covered by the 

 caudal bursa of the male. The vagina, the canal which penetrates the 

 papilla, is very narrow. Lodging the spicules of the male it serves as a 

 passage for the spermatozoids which the male pours into it during his 

 entire adult existence. It will be readily understood that it never ful- 

 fills the function of oviduct, since the inseparable union of male and fe- 

 male renders the discharge of ova through the vagina impossible. 



The vagina is continued into a short, enlarged uterus, about .6 mm (.024 

 inch) long and broad, which divides into two long cylindrical horns, 

 having a diameter of .3 mm (.012 inch) at the base and .25 mm (.009 inch) 

 at the apex. They are about three times as long as the intestine, about 

 which they coil in the most capricious windings. The uterus and its 

 horns are filled with ova, the development of which proceeds with the 

 age of the worm, as we shall see further on. Each horn at its apex 

 contracts abruptly into a short cone, and is continued by a small tube 

 about .05 mm (.002 inch) in diameter, which might be likened to a Fal- 

 lopian tube. After a distance of 3 mm (.118 inch) these tubes gradually 

 dilate into tubes of twice their diameter, filled with spherical, granular 

 corpuscles, compressed and crowded together in one or two rows. These 

 are the ovules, the tubes containing them, the ovaries. As long as the 

 uterine horns, these tubes are wound in a thousand different ways about 

 the intestine, then contract each into a tube as narrow as the Fallopian 



