336 



THE MICROSCOPE. 



of the wheels, it passes through a canal in the neck to 

 the mouth, which is situated lower down in the body ; 

 and there the food is crushed by teeth placed on the plates 

 of the jaw, with a hammer-like action; from this it passes 

 on through the alimentary canal for the sustenance of 

 the animal. 



BRACHIONJEA. Ehrenberg's genus Brachionus, "Spine- 

 bearing animalcule," belonging to the JKotatoria, are truly 

 interesting, from their perfect, high, and complex organisa- 

 tion. Some are entirely enclosed in a shell, others only 

 partially covered. Their structure, so beautiful and sym- 

 metrical, has caused them to become favourites with those 

 who delight in microscopical studies. Brachionus striatus, 

 " Striped shell animalcule" (No. 3, fig. 186), of an elegant, 

 jug-like form, has the transparent shell fluted lengthwise, 

 and likewise six scallops at the upper part; through which 

 the citron-coloured inhabitant pro- 

 trudes itself. Two hornlike processes 

 are appended to its under-side. 

 As occasions require, it sinks firmly 

 and securely within its crystal home, 

 which is sufficiently transparent to 

 permit a view of its organisation. 

 Its progress is effected by means of 

 ciliary processes. 



Brachionus Pala, or Anurce Cer- 

 vicornis, " Bent horn animalcule," is 

 possessed of double rotatory organs, 

 and four long processes, that project 

 above the oval shell. It measures 

 the 90th part of an inch. Brachionus 

 Ovalis?" Egg-shaped brachionus," is 

 remarkable for the strength of its 

 transparent shell, which is beyond 

 that of other shelled creatures. Its 

 projecting tail, as well as head, is at 

 pleasure withdrawn into its very 

 strong case. Brachionus Dentatus, 

 " Toothed brachionus." This active, 

 bright pink-eyed little creature, the 90th part of an inch 

 in size, is apparently enclosed in a two-valved shell, having 



Fig. 187. 



1, 2, Other forms of Ro- 

 tatoria. 





