niOPAGATlON BY DIVERS MODES. 147 



wlietlier they are bachelors disappointed in love, I 

 am unable to say ; but they are very inferior in 

 beauty to the ''gay and glittering crowd." 



For some weeks my Stentors abounded, and then 

 most of them suddenly disappeared. They could 

 not have ''moved," but probably "went to smash" 

 by a process peculiar to infusoria, and which Du- 

 jardin politely described as "diffluence." This 

 mode of making an exit from the stage of life is 

 more tragical than the ripping up so fashiormble 

 in Japan. The integument bursts, and its contents 

 disperse in minute particles, that in their turn dis- 

 appear, and scarcely leave a "wrack behind." 



The Stentors obey the injunction to "increase and 

 multiply" by '^self-division, which is either longitu- 

 dinal or oblique,"* and the nucleus, which plays 

 such an important part in infusoria, is band-like, 

 monileform, (bead-shape,) or round. When an 

 animalcule increases by self-division, a portion of 

 the nucleus goes with each part, and it is probably 

 the organ which stimulates the change. It is also 

 concerned in other modes of propagation, and it is 

 appropriately called by Owen the "seat of spermatic 

 force." "The anus is situated on the back close 

 beneath the ciliary circle;" and the "contractile 

 vesicle on a level with the ciliary wreath." Ac- 

 cording to Pritchard and Professor Cienkowski, the 



* Pritcliard, p. 581. 



