354 MR. H. M. BERNARD ON THE 



some of the nuclei in close proximity to the large nuclens just mentioned do or do not 

 belong to the organ under discussion or to the connective-tissue cells. Owing to the large 

 size of the hag-cells compared with the size of the external openings, the former are greatly- 

 crowded together, and at the edges of the sensory area the necks of the bags are very 

 long, and bend away at right angles under the cuticle (fig. 11 b). These appear to be the 

 commoner form in a small species (or ? young specimen) of Rhax from Tashkend. 

 (Figs. 11 a, 11 h, are enlarged from fig. 10.) 



2. (PI. XXXII. figs. 16 a, 16 b.) A small conical pit with the base of the cone outermost, 

 passes at its slit-like apex into a larger conical passage, the base being in this case innermost. 

 I have foxind it almost impossible to decide whether the outer pits open at the surface 

 of the cuticle ; I am inclined to think not, but that an exquisitely fine membrane spreads 

 over the mouth. I have found, for instance, small bodies apparently suspended over 

 the mouths of the pits in a manner which is difficult to explain, except on the assumption 

 that they are resting on a fine membrane ; but I am not at all certain of this. Prom the 

 narrow slit-like apex, where the cones pass into one another, a short chitinous tube 

 depends, from which the soft parts are often torn away. When the soft parts are in situ, 

 the appearance of the whole is as shown in the figures, and perhaps corresponds with 

 organs described by Bertkau. The outer apertures (?) of these organs measure about 

 12 n across, and are found on slight eminences, comparatively speaking, rather far apart. 

 They seem to be always present in limited numbers, generally along the outer edges of 

 the sensory areas under discussion. In fig. 12 a row" of them occurred along the left edge 

 of the dotted area, and on the right a few w^ere found even among the hairs. They 

 occurred also in the section fig. 10. 



3. Smaller conical pits (whether with or without membranous covers I have again 

 failed to decide) which pass very rapidly into a slit-like canal within the cuticle ; this 

 again rapidly changes into a tube of varying length which runs down freely among the 

 soft tissues subjacent to the cuticle. These pits seldom aj)pear circular when they reach 

 the outer surface of the cuticle ; they look, on siu'face view, heart-shajied, leaf-shaj)ed, 

 sometimes oval. They occur in great numbers (fig. 12), and, according to Bertkau, 

 are occasionally so numerous that their apertures (?) seem to run together to form 

 small common depressions. 



The exact details of the proximal ends of these organs I have been unable to make 

 out. The appearance is as if the soft parts had been crowded away from the cuticle, 

 with which, therefore, they remain connected by means of long tubes. These tubes 

 show remarkable modifications just before reaching their proximal oi'gans. Some of 

 Bertkau's figures appear to refer to the same, and give fairly well the general appearance 

 of the whole structure. Pigs. VI a & VI h give their appearance (seen by an oil 

 immersion in optical section on the limb, fig. 12), but I am as uncertain whether 

 I have interpreted the details correctly as I am as to what the functions of these 

 organs may be. In these figures (17 a, 17 b) it seems as if the jirotoplasmic process 

 running from the large bag-like terminal cell had been ruptured before it reached the 

 tube to the cuticle. I failed here also to make out for certain the position and character 

 of the nuclei of the bog-cells. 



