. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 1210 TUNICATA. surface of this organ : they are hollow in the centre, and emit a milky fluid, which is shed Fig. A, generative organs of Cynthia ampulla, situated in the fold of the intestine. (After Van Buneden.} a, stomach and its aperture (destitute of ceso - phagus);. b, rectum and anus; c, ovary, with its outlet into the cloaca; d, testicle, enveloping the edges of the ovary. B, magnified portion of the reproductive organs of Ascidia grossidaria. (After Van Beneden. ) a, testicle; b, ovary and ova. into the cl
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 1210 TUNICATA. surface of this organ : they are hollow in the centre, and emit a milky fluid, which is shed Fig. A, generative organs of Cynthia ampulla, situated in the fold of the intestine. (After Van Buneden.} a, stomach and its aperture (destitute of ceso - phagus);. b, rectum and anus; c, ovary, with its outlet into the cloaca; d, testicle, enveloping the edges of the ovary. B, magnified portion of the reproductive organs of Ascidia grossidaria. (After Van Beneden. ) a, testicle; b, ovary and ova. into the cloaca, and contains, or rather is almost composed of, spermatozoa, with dis- ciform heads and filamentous tails. The ovary is blackish, and is situated in the midst of the testicle. Its situation corresponds to that of the ovary of the Limaces among the Gasteropods, •which is surrounded by the liver. It is easily distinguished from the testicle by its colour and by the appearance of its contained eggs. The oviduct opens into the cloaca by the side of the anus. In Ascidia grossitlaria the eggs, seen through the walls of the ovary, are of a fine red colour, and are contained in separate sacs, the ovary appearing like a bunch of grapes (fig. 779. B). Van Beneden has distinctly seen in all of these ova the two germinal vesi- cles. The vitellus is at first white, but during development it becomes of a deep red. Bv the side of the ovary is another series of sacs without ova, and some free cells containing a great number of other more minute cells moving about in their interior, and which when shed swarm about like spermatozoa. These appear to constitute the male organ, and its disposition accords with that of the Amaroucium argus, and with that of the Bri/ozoa (Van Beneden). There remains much to be elucidated with regard to the generative functions of the Asci- dians. The male and female organs are always associated together, and are apparently each provided with efferent ducts. I
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