363 EXPLANATION OF THE PLATES!. 



is seen the exterior opening of the intestinal tube — 6, The ter- 

 mination of the obtuse extremity. 



Fig. III. The same tail viewed on its superior part. — a, The or« 

 ifice. — b. End of the tail. 



Fig. IV. The head of the lumbricoides seen on its anterior part, 

 -^aaafl, The body of the lumbricoides, or rather the four 

 white lines passing in a parallel direction on the surface of the 

 body. — b, Anterior view of the head, having three liemispher- 

 ical risings in the dead worm ; these eminences are pyrami- 

 dal in the living worm. In the centre is situated the trilabial 

 mouth. 



Fig. V. The external membrane of the lumbricoides, seen on its 

 internal part, — a bed, Longitudinal lines. — eee, Small rings, 

 occupying the space left by the longitudinal lines. 



Fig. VI. The male lumbricoides opened longitudinally, distend- 

 ed and retained in this position by means of six needles.— a, 

 The three hemispheres of the mouth. — a 6, Oesophagus. — b h. 

 The stomach and afterward intestine. — i. White vessels, 

 the origin of %vhich is concealed by the stomach. — c,The tail. 

 — e c, The penis.'— f e. Seminal vesicle. — rf, Intestine.— /^g*, 

 Spermatic vessels. 



Fig, VII. Spermatic vessels of tlie male lumbricoides out of their 

 natural situation. — a 6, Penis.— & c, Seminal vesicle. — c d. 

 Length and winding of the spermatic vessels, or vasa defe- 

 rentia. 



Fig. VIII. The female lumbricoides opened lengthwise. — a, Tri- 

 fid mouth. — a b, Oesophagus. — b c, Stomach. — e/. The great 

 intestine coloured black, the middle part of which ce is cover- 

 ed by the sphermatic vessels. — d d, Great white vessel situat- 

 ed under the stomach and oesophagus. — g". Extremity of the 

 oviduct. — o' //, The beading vagina — h, The point of division 

 of the two horns of the uterus, wiiicli, becoming narrower and 

 wonderfully folded, occupy all the space between k h. 



Fig. IX. The uterus of a female lumbricoides with the parts ad- 

 jacent, all removed from their natural situation. — a. External 

 wifice. — b bf Commencement of the two extremities of tlie ute- 

 rus itself. — e eee, Clusters of eggs included in these extrem- 



