280 SEA-SIDE STUDIES. 



increases, and finally becomes the general basis out of which, 

 or in which, an immense number of Ascidians are developed 

 by the process of "budding ;" so that from this one tadpole 

 embryo there arises a whole colony of animals, from which 

 in turn solitary tadpoles will issue, each of which will produce 

 its colony. Imagine a tadpole to be transformed into a 

 mature frog, this frog to swell his skin to an indefinite 

 extent, and under that skin to produce, by budding, some 

 hundreds of frogs, all living harmoniously 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 agitated, 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 zooph)i:e trough, and brought up a 

 quantity of newly-hatched Medusae in great activity. They 

 had just issued from the Polype {Laoviedea geniculata), 

 and on removing some of the Polype branches to the micro- 

 scope, the young Medusae were plainly visible in the cap- 

 sules, and were easily pressed out, whereupon they swam 

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

 panularian Polype with the young !Medusse in the capsule.) 

 Familiar as this sight was to me, it had not lost its marvel- 

 lousness. Here was a Pol}']ie, which the uninstructed eye 



enlarged, included the tail within it ; and the absorjition took place within the 

 sac thus formed. 



