64 



LIFE, IN ITS LOWER FORMS. 



are endowed with the power of spontaneous motion, and 

 apparently of choice as to locality, and have a definite 

 form, which is commonly pear-shaped, though the outline 

 is very flexible and variable. 



As the time of oviposition approaches, the umbrella 

 becomes gradually reverted, or turned inside out, the 

 ovaries swelling and protruding more and more, until they 

 occupy the principal portion of the animal. We believe 

 this to be general in the discoid Medusae, having observed 

 it in species that belong both to the Covered and Naked- 

 eyed divisions — namely, in the genera Chrysaora, Pelagia, 

 and Turris. 



In the case of the lovely little Coral-bead Medusa 

 (Turris neglecta), already alluded to, the phenomena are 

 well seen, the ovaries being orange or pale scarlet, studded 

 with proportionally large ova, of a rich purple hue. The 

 latter appear to escape from the walls of the ovaries, work- 

 ing their way out at the sides. They drop down on the 

 bottom of the vessel, where they move about slowly for a 

 while, but to no great extent, by means of their vibratile 

 cilia. By watching them we ascertain the following facts. 

 The gemmule, having adhered to some foreign substance, 

 grows out into a lengthened form, variously knobbed and 

 swollen, and frequently dividing into two branches, the 

 whole adhering closely to its support. After a day or 

 two's growth in this manner, a perpendicular stem begins 

 to shoot from some point of this creeping root, and soon 

 separates into four straight, slender, slightly divergent 

 tentacles, which shoot to a considerable length. The whole 

 is of a crimson hue, with the exception of the growing 

 extremities of the creeping root, which are pellucid white. 



