1431 COMPARATIVE STUDIES ON NEMATODES— HETHERINGTON 39 



CILIATION AMONG NEMATODES 



Former Views and Present Data 



It has been a generally held view that nematodes in company with 

 arthropods form the two animal groups totally devoid of cilia at any stage 

 in their existence. Fasten, however, disproved the opinion for arthropods 

 by demonstrating cilia as being present in the reproductive ducts. Shipley 

 in remarking upon the absence of cilia in these two groups believes the 

 condition is correlated with the tendency to form cuticula among nematodes 

 and with the great proclivity for chitinization in arthropods This view is 

 possibly correct as appears when one examines the variations of intestinal 

 linings among different species of nematodes. 



Prenant, who has made a special study of cilia and ciliary modifications, 

 has recently placed in the category of "bordure en brosse" the characteristic 

 intestinal lining of Ascaris megalocephala. An examination of one of his 

 original preparations of the sectioned intestine of this ascarid, showed the 

 lumen-ward end of the cells covered by a thick, rather finely striated 

 border. The elements, however, composing this border are not separately 

 distinguishable for the whole lining is a unit. Just beneath this border is 

 a distinct row of darkly staining basal granules which, too, are more or less 

 confluent and followed by a relatively deep homogeneous zone. This latter 

 portion gives way to the subcentral granular zone through the middle of 

 which is a relatively clear space. The nuclei are basal and lie in a region 

 containing numerous filaments running the long way of the cell. Other 

 authors in treating of this border have pictured the same condition but 

 called it either a cuticular border or a "Stabchensaum." 



Looss found a similar striated border upon the intestinal cells of 

 Ancylostoma duodenale but in the cases where individual rods or elements 

 were visible and separate he attributed them to a degeneration of the 

 border, as such were usually seen in adult worms, the younger specimens 

 exhibiting a more united and homogeneous appearance. Such a feature 

 is, no doubt, due partly to the fixation of the material as will be shown 

 later. Martini shows in his studies upon Oxyuris curvula identical struc- 

 tures in the intestinal ceUs (Figs. 46 and 47) and calls the lining a "Stab- 

 chenbesatz." In an alcohol preparation the "Stabchen" are not clearly 

 separated but in another, a gold chloride one, the lumen ends are appar- 

 ently free. Following the border is an indistinct layer of basal granules 

 from which fibrils may be traced rather indistinctly into the body of the 

 cell proper. Rauther also in working upon Enoplus describes the intestinal 



