228 FLOATING ASCIDIANS. PART in. 



formed by each of these creatures, which remains within 

 the parent till a solitary Salpa is hatched, and then 

 it comes into the water, and after a time produces a 

 chain of larvae. 



The aggregate young of the Salpa zonaria, instead 

 of being united end to end, are applied side to side, and 

 as the individuals are broad at one extremity and nar- 

 row at the other, they constitute groups continually 

 diminishing in size, which take a spiral form. 



The reproduction of the whole genus of Salpidse is 

 rapid and enormous. Dr. Wallich mentions that while 

 sailing between the Cape of Good Hope and St. Helena, 

 the ship passed for many miles through water so crowded 

 with the Salpa mucronata that it had the appearance 

 of jelly to apparently a great depth. The Salpse, which 

 were from one to two inches long, had yeUow digestive 

 cavities, about the size of a millet seed, which contained 

 diatoms, Foraminifera, Polycystinae, small shrimps, and 

 other microscopic creatures. 



