Notes on the Anatomy of the Ilyricqwda. 379 



pointed towards the second division of the alimentary 

 canal. In Z. grossipes these spines seem to be much 

 more numerous, and to extend over the anterior as well 

 as posterior portion of the lining. The passage of the food 

 through this portion of the alimentary canal is very rapid, 

 none being left in it in specimens killed within a few 

 minutes after a meal. 



The second part of the alimentary canal, the stomach, is 

 that in which the whole process of digestion goes on. It 

 has a thick muscular coat, and an epithelium composed of 

 a layer of large brownish cells, whose nucleus, easily 

 shown by the agency of acetic acid, is large, and of a some- 

 what conical shape. Throughout this epithelium there 

 appear to be a number of small glands, whose structure 

 I have not yet been able to determine, which secrete a 

 brownish fluid, by means of which the food is digested. 

 This stomach is plentifully supplied wdth blood-vessels. 

 The food seems to remain in it for a considerable time. 

 A peculiar feature of it is, that towards its posterior end 

 the remains of the completely digested food form a 

 solid column which becomes entirely surrounded with a 

 structureless membrane, from which portions break off, to 

 pass out of the stomach from time to time as faeces. 

 This membrane, which invests the fseces, was first pointed 

 out by Plateau. It yet remains to be discovered whence it 

 originates. 



The intestine in Lithohius is short, and much narrower in 

 diameter than the stomach. No process of digestion goes on 

 in it, the fasces merely passing quickly through it. It is 

 quite straight in Lithohius, though in other chilopods it is 

 always bent more or less. Dufour describes a small caecum 

 close to the anus; but neither myself nor Plateau have 

 found any traces of this. It has a covering of strong 

 muscular bands, and the cells of its epithelium, which are 

 much smaller than in that of the rest of the alimentary canal, 

 have large nuclei clearly visible without the aid of reagents. 

 They seem to secrete a colourless fluid, which probably aids 

 in assisting the passage of the faeces. 



The anterior glands are two large violet-coloured race- 



