8 ZOOPHYTES. 



contents approach maturity. Generally, they are somewhat lanceolate, or 

 resembling an inverted pear. Each cluster is suspended by a hollow stalk 

 from the lower part of the stomach in its vicinity ; and each cyst hangs 

 by a pedicle from this stalk.— Plate II. figs. 2, 3, 4, 5; Plate III. fig. 1. 

 Clusters 2-4, 6-8, natural size : Magnified, 3, 5, 7, 9; also fig, 16. 



The internal ovum seems connected with the stalk suspending the 

 bunch through the medium of its pedicle, which penetrates the cyst. 

 Perhaps this connection may be such as of the embryo in the vesicles of 

 the Sertularia, with what later naturalists denominate the placental co- 

 lumn. 



The integument of the cyst is rather of a fleshy consistence, either 

 opaque, or so thin and semi-transparent as to expose its contents. — PI. III. 



fig. 9.* 



Each contains a single embryo or foetus, which on maturity is expelled 

 slowly and gradually, as a minute, white, solid substance, from a dilateable 

 orifice at the extremity.— PI. III. figs. 10, 11, 12, 13. 



I was long doubtful whether two were not included in a single cyst, 

 especially as a dark septum seems to divide it. But one only in a spheri- 

 cal or ellipsoidal form belongs to each. Some are not half as large as 

 others.— PI. III. figs. 14, 15. 



Soon after expulsion an irregular zone or waving line may be recog- 

 nized on the circumference of the embryo, which, within a day, denotes 

 orioinating tentacula. In earlier stages the animal resembles a star with 

 obtuse rays, or the spokes of a wheel ; figs. 20, 23. The centre is next 

 prolonged in opposite directions : on the one side as extending oral palpi, 

 on the other as the neck or stalk of the hydra. 



But these are of slower progress ; and meanwhile the discoidal or 

 circumferential tentacula exhibit enlarged extremities in their elongation, 

 whereon the nascent animal sustaining itself, reversed from the ultimate 

 natural position, can voluntarily change its place. Now, the central por- 

 tion forming the stomach augments in length, and decreases in thickness ; 



* Considerable latitude must be allowed to tlie signification of fleshy, mebranaceous, 

 gelatinous, and the like. 



