﻿A TKINSON—COPRIX US 



to its convexity, is not approximately perpendicular to the axis of 

 the stem, but its outer portion is strongly depressed (see dia- 

 gram IV), because the strong epinastic growth of the margin of the 

 pileus causes it to curve downward. In such cases the sections, 

 to be transverse to the salients and also parallel with their direction 

 of growth, must be more or less strongly oblique to the axis of the 

 stem. It can be seen readily that in such cases the young lamellae 

 would be cut parallel with their direction of growth in width, only 

 on one side of the basidiocarp, unless the latter had previously been 

 cut into two longitudinal halves. Obviously this situation cannot 

 well be determined in advance; but if entire 

 basidiocarps are used, the situation can be 

 interpreted, after cutting through the near 

 side of the object, by an examination of the 

 median sections parallel with the stem axis. 

 The remaining half can then be oriented in 

 such a way as to make the sections in the 

 desired direction. If longitudinal halves 

 of basidiocarps are used, however, a few 

 sections can first be made on the stem side 

 in order to determine the orientation of 

 the young hymenophore. 



The further development of the lamellae 

 consists in the radial extension of the 

 salients originating in the downward fold- 

 ing of the palisade area, progressing in a 

 centrifugal direction until the margin of 

 the pileus is reached. The broadening of the lamellae, that is, 

 their increase in breadth, is brought about not only by increase 

 in size of the elements now present, and by continued growth 

 of the trama hyphae of the young lamellae, but also by the 

 increase in number of the elements of the hymenium and sub- 

 hymenium throughout. 



As the young basidiocarps become older, in order to obtain 

 sections perpendicular to the origin of the lamellae, or parallel with 

 their direction of growth, the cuts must be made more and more 

 oblique to the axis of the stem, or finally perpendicular to it. This 



