14 WILLIAM PATTEN. 



thoroughly macerated these cells fall off, and the outer mem- 

 brane is then absent. The sharp inner wall, the investing 

 membrane, and the axial nerve produce a picture very much 

 like that of a Vertebrate medullated nerve. 



In macerated preparations the cell usually breaks just 

 beyond the spindle, as in figs. 5 — 7, but in some instances 

 nearly the whole tubule is isolated. When the tubule 

 breaks near the spindle, the axial nerve usually projects a 

 long distance from its open end, either as a single fibre 

 (figs. 5, 6) or as a delicate brush of fibrillse (fig. 7). Beyond 

 this region it breaks with a clean fracture, as though made of 

 glass, and a protruding axial fibre is rarely seen. Towards 

 its outermost end the axial nerve cannot be seen under any 

 circumstances, but this is due to the fact, I believe, that the 

 canal in the tubule is so small that it is completely filled by 

 the nerve. The tubule is thickest where it enters the cuticular 

 canal (fig. 1, s. ch. t.) ; but it becomes smaller and smaller, as 

 well as the canal in which it lies, until, at the surface, the tubule 

 just fills the canal. In surface views (fig. 2) the black dot is 

 the pore of the canal, completely filled by the tubule; the clear 

 halo surrounding it is cuticula more transparent than the 

 rest. 



The stalk of the gustatory cells, just below the 

 spindle, is very finely striated, and when macerated and 

 broken, as in fig. 5, the striation is seen to be due to the 

 presence of excessively fine fibrillse, much more numerous 

 than those in the spindles. There are no nuclei to be seen on 

 the long nerve-like stalk of the cell, between the spindle and 

 the nucleus. On the distal side of the nucleated part of the 

 cell are usually a few yellowish-brown pigment granules, that 

 in some cases are large and very numerous, as in fig. 4. 



The nucleated ends of the gustatory cells are arranged in 

 long clusters along roughly parallel lines, each band of cells 

 corresponding to a line of pores. Judging from the number 

 of cells it contains, the cluster at gs. c, fig. 1, is probably 

 connected with a row of pores running the whole length of the 

 spine, although this is difficult to determine with certainty. 



