POLYPES PRODUCING JELLY-FISH. 297 



to an indefinite extent, and under that skin to produce, 

 by budding, some hundreds of frogs, all living harmo- 

 niously together, each fed by all — further imagine this 

 colony producing at last a few solitary tadpoles, and 

 you will have some conception of the paradox presented 

 by our compound Ascidians. 



Nor is this paradox without parallels. The other 

 day I noticed the surface of the water in my pan agi- 

 tated, as if scores of hairs were at various points thrust 

 upwards. Nothing else was visible with eye or lens. 

 Suspecting, from a certain pulsating motion, that it 

 was caused by young Medusae, I dipped the zoophyte 

 trough, and brought up a quantity of newly-hatched 

 Medusae in great activity. They had just issued from 

 the Polype {Laomedea geniculata), and on removing 

 some of the Polype branches to the microscope, the 

 young Medusae were plainly visible in the capsules, and 

 were easily pressed out, whereupon they swam away 

 like the others. (Plate IV., fig. 1, represents a Cam- 

 panularian Polype with the young Medusae in the cap- 

 sule.) Familiar as this sight was to me, it had not 

 lost its marvellousness. Here was a Polype, which the 

 uninstructed eye could not distinguish from a seaweed, 

 producing scores of Jelly-fish ; and these Jelly-fish, if 

 their days were spared, would in due time produce 

 Polypes. Imagine a lily producing a butterfly, and the 

 butterfly in turn producing a lily, and you would 

 scarcely invent a marvel greater than this production of 

 Medusse was to its first discoverers. Nay, the marvel 

 must go further still ; the lily must first produce a whole 



