2o6 LAXGDOX. [Vol. XI. 



in which the gland-cells are more abundant suggests that the 

 function of these nerve-fibres may be to control the secretion 

 of the gland-cells. But the fact that the fibres are also found 

 among the supporting cells and in the buccal epithelium indi- 

 cates that, even if the above suggestion be true, this is not 

 their only function. The intraepidermal fibres may have for 

 their function the control of the general metabolism of the 

 epidermal cells, or it may prove that their function is sensory. 

 Sense-organs. — Although no difficulty has been experienced 

 in staining the intraepidermal nerve-fibres, there has been an 

 uncertainty in the action of the stain on the sense-organs. No 

 difficulty has been found in recognizing the latter, whether 

 stained or unstained, in all preparations in which they occur. 

 In sense-organs which are unstained, even in cases in which it 

 is impossible to distinguish the separate cells, the organs them- 

 selves may be easily identified by the elevation of the cuticula 

 above them and by the layer of deeply stained covering cells 

 around them (PI. XIII, Fig. 3). In rriany of the sense-organs 

 the sense-hairs, sometimes stained, sometimes clear, could be 

 seen projecting from the cuticular elevation, thus affording an 

 unmistakable evidence of the presence of the sense-organs. 

 When the sense-cells of the sense-organs are stained (PI. XIII, 

 Figs. 1 1 -14), the covering cells are sometimes stained, some- 

 times unstained. In all cases the basal cells of the sense-organs, 

 as well as those in the epidermis, are unstained. The sense-cells 

 themselves have in my preparations taken the stain so differ- 

 ently from any other cell of the epidermis that they could be 

 easily distinguished even under a low power. The covering 

 cells of the sense-organ and the supporting cells of the epider- 

 mis stain black or a blackish brown, and no trace of a nucleus- 

 can be seen in them. The sense-cells stain a reddish brown, 

 and usually the nucleus shows as a clear oval spot. This dif- 

 ference between the color taken by the supporting cells and 

 that taken by the sense-cells must be due to some intrinsic dif- 

 ference between them; the nerve-fibres of the sense-cells have 

 the same brown color, instead of staining black like the other 

 nerve-fibres. Since these sections were prepared, the sense- 

 cells have darkened a little, and in some cases the nuclei have 



