200 



LIFE, IN ITS INTERMEDIATE FORMS. 



else than the month, its place being cansed by the inver- 

 sion of the fore parts of the body, permanently in some 

 species, as Rotifer, but in others, as Scaridium, Furcel- 

 laria, &c, transiently, the month being brought to the 

 exterior when in action. The hammer-like pieces are the 

 representatives of the upper jaws (mdndibula), and the two 

 halves of the table-like piece, against which they work, 

 are the representatives of the lower jaws {maxillce) of 

 Insects. 



The food, after having been subjected to the pounding 

 and crushing action of these hammer-like jaws, passes 

 off behind through a slender gullet into a capacious sto- 

 mach, into which bile is poured from glands (either a 

 single pair or very numerous) which are appended to it. 

 This is succeeded by an intestine, and this by a rectum, 

 which terminates in an orifice behind the foot. 



It is a curious circumstance that there exists one genus 

 in this Class — hence named Asplanchna — which has no 

 intestine nor any posterior outlet to the stomach, the fcecal 

 portions of the food being regurgitated and expelled from 

 the mouth. Still more remarkable is the fact, that all 

 the males in the Class are entirely destitute of the diges- 

 tive apparatus ; neither mouth, jaws, gullet, stomach, nor 

 intestine being found, nor any vestiges of these organs, in 

 any male Rotiferon. 



So far as has been observed, the sexes are separate 

 throughout the class. The peculiarity just noticed is 

 not the only one that distinguishes the sexes. The male 

 Eotifera are invariably smaller, less fully organised, and 

 more short-lived than the females ; they commonly have 

 scarcely any resemblance to their partners, though the 



