424 GENERAL HISTORY OF THE INFUSORIA. 



in Noteus. This is possibly the structure alluded to by Mr. Gosse as " several 

 yellow glandular (?) spots " seated on the top of the cushion of the dental 

 organs of Asplanchna (XXXVIII. 28), and the same with the yellowish, 

 clear, horny-looking masses mentioned by Huxley va. Lacinularia (XXXVII. 

 19 ^) and Bracliionus. The last-named natui'alist refers these bodies to the 

 *' homy skeleton " (see p. 412). Leydig considered they might possibly be 

 " saHvary glands." 



The epithelium of the aUmentarj^ canal has probably a glandular purpose : 

 its large cells are filled with a granular matter, and many oil-vesicles, besides 

 a nucleus. The number and large size of these gastric cells have been already 

 illustrated (see p. 419) ; they are mostly coloured — yellow or yellowish brown, 

 with sometimes green spots interspei-sed. Ehrenberg remarked these ceUular 

 accumulations, and advanced the hypothesis of their homology with the liver 

 of higher animals. The colouring matter was consequently esteemed to be 

 the bile. We have seen that Rymer Jones has assigned the fimctions of a 

 liver to the so-called '' pancreatic " sacs, or " gastric glands." However, 

 most naturalists favour Ehrenberg's view ; among them are Dujardin, Sie- 

 bold, Leydig, and Dairy mple. The belief, indeed, of the great Berlin natu- 

 ralist was, that the ceUs grew from the exterior of the wall of the alimentary 

 canal, and were so many saccular appendages ; this view modern research 

 does not countenance, but affirms the presence of the ceUs within the canal. 

 The examples of secerning cells given by Ehrenberg deserve to be mentioned. 

 He remarked that in Enteroj^lea the biliary cells and ducts were most pro- 

 nounced, and that there was great accumulation of cellular or glandular ele- 

 ments about the intestine of Rotifer, CalUdhm, and Philodina ; in the last 

 two he also asserted that the mass becomes coloured by colouring particles 

 swallowed by the animals. 



Mr. Gosse puts the question whether the little granular body near the 

 tip of the pedicle of Melicerta is a secerning gland for the secretion of an 

 adhesive glue, by which the foot adheres, as in Monocerca. This faculty 

 of secreting an adhesive matter from the end of the pseudopodium is sur- 

 mised by Perty to be possessed by several Rotatoria, viz. by ConocMlus, La- 

 cinularia, (Ecistes, Floscidaria, Limnias, Tuhicolaria, and Stephanoceros. 

 This idea is countenanced by Cohn (Zeitschr. 1855, p. 439), who inclines to 

 the belief that the solid-lookmg elongated- oval bodies situated at the poste- 

 rior extremity of the abdomen of Bracliionus and other species, and usually 

 considered muscular (moving the tail-process), are rather of a glandular na- 

 ture, and possibly secrete an adhesive glue to fix the animal. More recently 

 (Midler's ArcMv, 1857, and A. N. H. 1857, xx. p. 292) Leydig has accepted 

 this view, and thus treats of these structures in Hydatina senta : — " The 

 clavate bodies in the tail consist of a delicate envelope and pale molecular 

 contents, in which beautiful nuclei, each with a nucleolus, may be distin- 

 guished ; in many individuals, small fatty points are also present in variable 

 amount. I regard the organs in question as glands, which in their position 

 and fimction correspond with the caudal glands of Enoplus for examj)le ; they 

 open at the apex of the caudal appendages (Fiisszangen) ; and as the worm 

 just mentioned ' can attach itself firmly to the object-bearer by the posterior 

 extremity of the body, in order to carry the body round this point with a waving 

 motion,' so also can the Hydatina fix itself by the tips of the caudal append- 

 ages, probably by means of the sticky substance excreted here. It seems to 

 me also, that in a certain upright position of the caudal appendages, I have 

 detected the opening at their tip." 



Other large vesicles, which some think may be glandular, occur in different 

 parts of the body, and in the foot- process of several genera. Such are noticed 



