126 THE VOYAGE OF H.M.S. CHALLENGEE. 



undermost glands is figured. These glands project into the interior of the intestine, and 

 are, as far as I know, the only true glandular bodies which stand in connection with the 

 alimentary canal. They are invested by the same membrana intima as the wall of that 

 part of the oesophagus, at the end of which they are found. The form of the cells which 

 compose them is nearly the same. The whole of the gland must be considered as having 

 taken its origin from an excrescence and bending towards the wall of the intestine, of the 

 hinder part of that cesoj^hagus. 



In regard to the structure of the remaining part of the intestine I do not ■ftdsh to 

 enter into any details. I only observed that the structiu'e of the wall of that part which 

 follows immediately after the oesophagus, and of the cseca, which penetrate as a rule 

 as far as the sixth joint of the leg, is nearly the same. We find this wall everywhere beset 

 with extremely numerous tubes or villi, which in some genera (^Nymphon) are of a 

 shorter and more rounded form, and in others [Colossendeis) are very slender and almost 

 cyhndrical. While the outermost part of the wall is formed of a single row of large 

 distinct nucleated cells, these vdli show a multi-cellular structure also. Each of these 

 cells contains numerous globules, which for the most part seem to be of a fatty 

 nature. The form of the cells is different, but they are commonly rounded. I call 

 them cells, because each of the bodies has a distinct oval nucleus with a small nucleolus. 

 As has been observed by almost all authors writing on the structure of the wall of the 

 intestine, these cells often become detached from the wall, and are found lying loose in 

 the contents of the alimentary canal. The nuclei in the cells of these villi were by no 

 means easily observed in all the sections I studied. They were very distinct in the cells 

 of the villi of Colossendeis prohoscidea, Sab. (sp.). 



It seems to be characteristic of the genus Colossendeis that the cteca destined 

 for the different legs should branch off from the main duct, which runs straight from the 

 proboscis to the abdomen, very close to one another, and close also to the place where the 

 oesophagus communicates with the intestine ; at least I observed that in the three species 

 of Colossendeis I studied (PI. XVII. fig. 1). The number of lateral caeca given 

 off at both sides of the main duct is six in Colossendeis. Of these the first two are 

 rudimentary, one being the rudiment of those destined for the mandibles, the other (the 

 first lateral pair) being that for the proboscis. Each of the four remaining cseca, of 

 which the hindermost pass through a much longer part of the body before penetrating the 

 leg than do the more anterior ones, shows a considerable swelling in the lateral processes, 

 at the ends of which the legs are inserted.^ The anal aperture of Colossendeis (PI. XVII. 

 fig. Id) is an oval-shaped slit. It is not placed terminally or in the median line of the 

 abdomen, but laterally. 



1 Ou a transverse secti(5n of the body of a Colossendeis between the lateral processes for the .second and for the 

 third pair of legs, five round sections of the intestine are seen placed close to one another. This furnishes a good 

 opportunity of comparing tlieir structure, but no difference is observed. Compare fig. 14 of Plate XXI. 



