SECT. ir. PROPAGATION OF INFUSORIA. 75 



more globular form, and secretes a gelatinous substance 

 from its surface, which hardens into a case or cyst, in 

 which its body lies unattached and breaks up into 

 minute ciliated gemmules, which swim forth like zoo- 

 spores as soon as they come into the water by the thin- 

 ning away of part of the cyst. In fact the animal is 

 resolved into its offspring, which, as soon as free, gradu- 

 ally acquire the parent's form, though at first they may 

 bear no resemblance to it. The scarlet Peridium seen 

 by Mr. Carter in the Bay of Bengal is propagated in 

 this manner. For the parent Peridium is broken up 

 within its cyst into from two to four new ones, each of 

 which when set free and grown up might undergo the 

 same process. 



The Loxades bursaria increases by three distinct 

 methods, and sometimes by two at a time. In autumn, 

 or the beginning of winter, six or eight germs contain- 

 ing granular matter and one or more hyaline nuclei 

 are formed within the animal, each enclosed in two 

 contractile cysts : they lie freely in the cavity of the 

 body, and come one by one into the water through a* 

 canal ending in a protuberance in the skin. During 

 this time the pulsations of the vesicles within the 

 Loxades are continued, but the gyration of the green 

 particles is suspended till all the germs are excluded 

 and swim away, and then it is renewed as vigorously 

 as ever. At first the young are totally unlike their 

 parent, but by degrees acquire its form. The Lox- 

 ades is also increased by division, sometimes across, 

 sometimes longitudinally, and, in the latter case, one 

 half is occasionally seen to contain germs which have 

 been excluded before the other half had separated, so 

 that the two distinct systems of propagation are simul- 

 taneous. 2 



The Vorticella nebulifera and some others of the 



2 ' Lectures on Comparative Anatomy,' by Professor Owen. 



