120 VIGNETTES FROM INVISIBLE LIFE. 



ing on to the mature stage. Then two or more go 

 forward to this condition where only one would 

 otherwise have done so. 



Another form of the Acinetina (Dendrosoma 

 radians) resembles a gnarled and irregular tree, 

 with stumpy branches, from which the charac- 

 teristic radiating tentacles emanate. It is rather 

 rare ; and until lately its history was involved in 

 obscurity. It has now been shown that, in 

 addition to the methods already described, this 

 class is propagated by means of spermatozoa, 

 very much like that already described in Acti- 

 nopltrys. 



It is important to notice the character of the 

 tentacles in Acinetina as contrasted with those 

 in Aciinophryina. In the latter they are finely 

 pointed spines, which pierce and draw the prey to 

 the body, where a mouth is extemporised to receive 

 it. In the former they are tubular and tipped with 

 suctorial discs, which spread a little around the 

 captured victim. Small infusorians coming in con- 

 tact with them are instantly arrested in their course, 

 and compelled helplessly to adhere, while the Acine- 

 ton draws out their soft interiors. In clear speci- 



