26o American Quarterly Microscopical Journal. 



For an understanding of the relations of these clusters, and for a 

 hint of their possible origin, a glance at the unmodified epidermis 

 ,will be desirable. The deeper layer of this consists of columnar 

 cells, much wider, but shorter, than those of the sensory bodies. 

 Figs. 2 1, 2 2 and 23 are examples, the first being the commonest 

 form. More or less oval or spherical cells (represented by Figs. 

 6 and 20) intervene between these and the superficial layer, and 

 among them the irregular masses of pigment are distributed. 



It is evident that any unusual developmental stimulus applied to 

 the columnar epidermal cells at a given point, determining their 

 elongation and more rapid multiplication, would gradually crowd 

 away and flatten, by compression, the more superficial cells, result- 

 ing, if continued, in the protrusion of the columnar cluster through 

 these layers, and that, at the same time, the columnar cells them- 

 selves would be forced, by mutual pressure, at least in the interior 

 of the mass, into forms similar to those delineated in the plate. 



The advantage of these compact little masses as a sensory appa- 

 ratus over the adjacent epidermis, presenting, as they do, a medium 

 anatomically continuous between the outer force and the seat of 

 the inner impression, is very evident, especially when they form 

 distinct elevations of the surface. It is not impossible that, 

 through their rod-like cells, they may even transmit vibrations, and 

 so minister to a more delicate sense than that of touch. Just what 

 this sense may be, of course, we cannot tell, and we can probably 

 do no better than to follow Leydig in regarding these and similar 

 structures as the organs of a sixth sense, of whose character we 

 must remain forever ignorant. 



State Laboratory of Natural History, 

 Normal, 111. 



SPORES, WITH A SPORE (GLOSSARY. 



BY C. L. ANDERSON, M. U. 



{Received February jyf/i, i<S'/(p.) 



The history of a spore would be the history of a life — a life in 

 its dealings with matter. It may be the longest or shortest life, 

 and the smallest or greatest quantity of matter. The actual life 

 of a spore may be limited to a single moment, for in the act of 

 birth it dies. That is, in freeing itself from the matrix in which 



