470 



ZOOPHYTES. 



hang down like a fringe around its margin. From the four 

 angles of the mouth, which, even in the youngest detached 

 animal, admits of being greatly extended and protruded, pro- 

 longations are put forth, which form the four large tentacula of 

 the adult. And finally the generative organs make their ap- 

 pearance in four chambers disposed around the stomach ; which 

 are occupied by plaited membranous ribands, containing sperm- 

 cells in the male, and ova in the female ; and the embryoes 

 evolved from the latter, when they have been fertilized by the 

 agency of the former, repeat the extraordinary cycle of pheno- 

 mena which has been now described. 



308. In connection with the preceding, it will be convenient 

 to mention two curious little marine animals of frequent occur- 

 rence, the true place of which in the scale it seems difficult to 

 determine, but which, having the free swimming habits and the 

 soft texture of the Medusae, have been very commonly ranked 

 as members of the same class. One of these is the Cydippe 

 pileus (Fig. 228, A) very commonly known as the Beroe, which 



FIG. 228. 



A, Cydippe pileus with its tentacles extended; B, Beroe Forskalii, showing the tubular prolongations 



of the stomach. 



designation, however, properly appertains to another animal (B) 

 of the same grade of organization. The body of Cydippe is a 

 nearly globular mass of soft jelly, usually about three-eighths of 

 an inch in diameter ; and it may be observed, even with the 

 naked eye, to be marked by eight bright bands, which proceed 

 from pole to pole like meridian lines. These bands are seen with 

 the microscope to be formed of rows of large cilia, which are in 

 a state of pretty constant vibration, though sometimes they are 

 at rest ; and if the sunlight should fall upon them when they 

 are in activity, they display very beautiful iridescent colors. The 

 mouth of the animal, situated at one of the poles, leads to a 

 stomachal cavity of cylindrical shape, which extends about as 

 far as the centre of the body, and then narrows into an intestinal 

 tube which terminates at the opposite pole ; from this stomach 



