152 BULLETIN OF THE 



d. Dermal Bodies. 



Various opinions have been held by different authors as to the mor- 

 phological value of the dermal bodies. Keferstein und Elders ('61) de- 

 scribed them as glands, Leydig ('61) regarded them as sensory organs; 

 but later writers have inclined to the former view. Andreae ('81) de- 

 scribed three varieties of these organs, whereas Vogt und Yung ('88) 

 made the claim that the sensory organs, Andreae's third variety, do not 

 exist, and that all of the glands are merely modifications of one sort. As 

 to the first statement, they are undoubtedly correct ; but to the latter 

 view I am unable to assent. The transition from one sort of gland to 

 the other,, though plausible from surface views such as given by those 

 authors, is only apparent. For if one examines carefully prepared sec- 

 tions, the seeming similarity gives way to a well marked difference. Not 

 one of the glands is actually unicellular, as claimed by Vogt und Yung, 

 and the multicellular contain never less than five cells, which serves 

 to separate them clearly from the other kind, which is always bicel- 

 lular. Moreover, their behavior toward staining fluids is very differ- 

 ent. For while the bicellular glands take up hematoxylin with such 

 rapidity as to become almost black in a few seconds, the multicellular 

 are but little affected by this reagent. Carmine solutions stain the two 

 about equally, but bring out the nuclei, which are invisible in a hema- 

 toxylin stain. And, finally, the morphological elements of the two sorts 

 are essentially different, as will be shown. The old classification of bi- 

 cellular and multicellular glands will therefore be retained, and the 

 structure of each will be examined more in detail. 



The bicellular glands, when viewed, even in the living animal, directly 

 from above, display a clear zone along the line of the partition wall be- 

 tween the cells. This is invisible if the gland be viewed from the side, 

 or at a considerable angle, and gives rise to. various images if the line of 

 sight be more or less nearly perpendicular to the surface.' As the pa- 

 pillae which contain the glands have sloping sides, never exactly alike, 

 it is easy to understand how views of the glands from many different 

 directions may be had from a surface inspection, and how the various 

 images may give the appearance of a series from the bicellular to the 

 multicellular gland. If one examines, however, sections of the skin per- 

 pendicular to the surface (Figs. 4, 5), the bicellular glands appear at 

 once as a distinct type. Ordinarily spherical, they may often be found 

 mutually flattened where several lie closely pressed together. They 

 vary in diameter from 40 to 50 fi, and present very different appearances 



