SEA-BLUBBEHS. 
83 
CHAPTER IX. 
Acaleph.® ( Sea-blubbers ). 
Continued. 
^ e propose now to speak of the reproduction of the 
Medusae, at least of the Discophora, or iimbrelliform fami- 
lies, for of the other orders we know little, except their 
forms. Some of the phenomena of Alternate Generation 
have been described in a previous paper, a compound hy- 
droid Polype giving birth to tiny Modus®, which after- 
wards produce a generation of Polypes. Wo have now to 
contemplate the counterpart of this wonderful process,— a 
free swimming Medusa producing gemmules, or motive 
eggs, each of which, becomes a stationary Polype, and ulti- 
mately throws off a number of Medusa;. 
The ovaiies in these animals are ordinarily placed in 
contact with the walls of the central stomach, or with the 
i a esti\ e canals that radiate from it across the disk. At the 
season of development they consist of numerous ribands 
o membrane, much folded and convoluted, and fringed 
Th" * re ° P 0IK l e ut filaments, covered with vibratory cilia. 
c ova aio globose, gelatinous germs, existiug in immense 
mu titudes, which on oxtrusion are strongly ciliated, and 
ear a close resemblance to Infusorial Animalcules. They 
