﻿BOTANICAL GAZETTE 



Origin of the lamellae— The first evidence of the origin of 

 the lamellae are radial salients of the hymenophore fundament, 

 just described, which project downward (figs. 28, 31, 32, 34, 35, and 

 37). These salients are formed not only by the more rapid increase 

 of the elements of the palisade layer but also by the elongation 

 of the subadjacent trama cells of the pileus which support or bear 

 them. The continued growth of these trama cells gives rise to 

 the trama of the lamellae. In the early stages of the origin of the 

 lamellae there is a striking difference in the character of the trama 

 cells in C. atramentarius and those of C. comatus. In C. comatus 

 the rather weak development of the trama hyphae in the very young 

 lamellae, and the rather open mesh which they form, contrasts 

 strongly with the compact tissue formed by the elongation of the 

 trama extending from the pileus into the young gill salients of 

 C. atramentarius. The compactness of the trama tissue at this time, 

 together with the evidence of the elongation of its cells in the 

 direction of the growth of the salients, gives the impression that this 

 is a factor in the origin of the salients, which assists in thrusting 

 or shoving downward the palisade tissue along the radial areas on 

 which the young lamellae arise. The elongation of these trama 

 cells of the pileus, subadjacent to the salients, is recognized not 

 only by the form of the cells, but also from the fact that they stain 

 less deeply than the intervening trama cells of the pileus sub- 

 adjacent to the hymenophore (figs. 32 and 37). 



Figs. 27-32, 34, and 35 are from the same basidiocarp, the 

 sections all being parallel with the axis of the stem. Fig. 27 is from 

 a median section; fig. 28 is tangential on one side where the young 

 gill salients are quite distinct; fig. 29 is from the opposite side of 

 the basidiocarp where the young hymenophore is still in the pali- 

 sade condition before the appearance of the salients; fig. 31 is from 

 the gill side, but nearer the margin of the pileus; and fig. 32 is the 

 same more highly magnified. Fig. 34 is from a portion of the same, 

 still more highly magnified to show the details of the palisade layer 

 with the very earliest evidence of gill salients. 3 of which are shown. 

 Fig. 35 is from the area of fig. 34 including the middle salient but 

 still more highly magnified. In both figs. 34 and 35 the palisade 

 layer of cells is very clearly shown, particularly so in fig. 35. The 



