20 Mr. r. II. Gosse on Asplanchna priodonta. 



the prey. Then the network of fibres contracts again and the 

 prey is secured. The jaws, with their cushion, are placed within 

 this cavity at the front anterior end ; and immediately beneath 

 the cushion {7iot at the bottom of the crop) opens the long delicate 

 duct, composed of longitudinal and annular contractile tissue, 

 which leads to the stomach. It is capable of immense dilatation, 

 but commonly takes the form of a slender tube with the lower 

 extremity swollen, where an oval pancreatic gland is attached on 

 each side. The passage of a small morsel, such as a Chilomonas 

 (see fig. a), shows that the walls of this organ are thick, leaving only 

 a slender tube when corrugated. The stomach consists of several 

 rounded lobes or sacculi, arranged in a somewhat hemispherical 

 form, the convexity being downward. It is always of a yellowish 

 hue. There is no anal orifice to the stomach nor any intestine ; 

 the remains of the food when digested are regurgitated by the 

 contraction of the viscera and discharged through the mouth. 



The reproductive system consists of the ovary, the ovisac, the 

 contained ovum or embryo, the oviduct, and the vaginal orifice. 

 In no specimen have I seen the ovary horned or band-shaped, 

 but roundish and very small. It is seen in fig. a with its nuclei, 

 with the ovisac wrinkled up in front of it : in figs, h and i it is 

 behind and somewhat above the ovisac, which contains a deve- 

 loping ovum. Cells are seen forming in the ovum, and there 

 are several large oil-globules of a salmon colour and of a high 

 refractive power. Possibly the colouring matter of these reser- 

 voirs may be resolved into the red pigment of the eyes, and the 

 ' yellow of the jaw-cushion and other parts. The ovum pi'oduces 

 the living young in the ovisac, which, when matured, occupies the 

 whole lower part of the parent, if a female young ; but the male 

 is much smaller. At length it escapes through the oviduct and 

 vaginal aperture, and immediately swims freely away. All its 

 organs, the eyes, teeth, stomach, muscles, rotating cilia, &c., can 

 be seen with perfect distinctness long before expulsion, and its 

 motions are strong and voluntary. On the upper side of the 

 oviduct sits a contractile bladder, which when full is perfectly 

 globular and small ; being scarcely, if at all, larger than the two 

 pancreatic glands put together. Round this, attached at or near 

 its base, passes on each side a tortuous thread apparently glan- 

 dular, which goes up along each side of the ventral region, and 

 is attached to the head-mass behind the jaw-cushion. The mid- 

 dle part of each thread is wrinkled into a large plexus of four or 

 five pairs of doublings, laid with some regularity ; on this plexus 

 are placed four tremulous tags directed inwards ; making eight 

 in all. None are visible on any other part of the threads. The 

 presence of these organs, as well as of the contractile bladder, in 

 the female, shows that these are not connected with impregnation. 



