338 ATKINSON— MORPHOLOGY AND [April 23, 



The situation in certain species of Coprinus, where the margins 

 of the gills are attached to the stem before maturity, and break 

 away during the expansion of the plants, has for a long time inter- 

 ested me, and I have intended to investigate certain of the species 

 for the purpose of comparing the situation in this genus with that 

 described in Amanita rubescens^^ by deBary, A. miiscaria'^^ by Bre- 

 feld and in Amanitopsis vaginata^^ by myself, where there is no 

 general prelaniellar cavity, and the first evidence of the lamella is 

 the differentiation of a series of radial trabeculse in the hymeno- 

 phore primordium, continuous with the stem and trama of the pileus. 

 This investigation was delayed, however, until the autumn of 1914. 

 Material of three species, Coprinus comatus, atranientarius and 

 micaceus, was studied, and the results will be published in another 

 paper. This much may he said here, that these three species do not 

 belong to the Amanita type but to the Agaricus type. There is a 

 strong, annular, prelaniellar cavity in Coprinus comatus, a weak one 

 in C. atramentarius and micaceus, but in all three the lamellae orig- 

 inate as downward-growing salients of a level palisade zone, exactly 

 as described here for Agaricus rodmani, the only difference being 

 in those specific features relating to the structure of the lamellae. 

 Levine based his interpretation of the origin of the lamellae in 

 Coprinus micaceus on complicated and rather well advanced stages 

 of their development. Had the origin of these complicated struc- 

 tures been sought it is probable that the origin of the lamellae would 

 have been found. 



Of the plants thus far studied the following species may be 

 mentioned as examples of the Agaricus type in which the origin of 

 the lamella has been clearly and correctly described, those by Hoff- 

 mann more than half a century ago. Agaricus carneotomentosus 

 {Panus torulosus) by Hoffmann'*^ (1856, p. 145) ; Cantharellus 



39 De Bary, A., " Morphologie und Physiologic der Pilze, Flechten und 

 Myxomyceten," Leipzig, 1866. " Vergleichende Morphologie and Biologie 

 der Pilze, Mycetozoen und Bacterien," 1884. " Comparative Morphology and 

 Biology of the Fungi, Mycetozoa and Bacteria," Oxford, 1887. 



*° Brefeld, O., " Botanische Untersuchungen iiber Schimmclpilzc," 3, 

 Basidiom3^ceten, L, I.-IV., 1-226; pis. 6-1 1, 1887. 



41 Atkinson, Geo. F., "The Development of Amanitopsis vaginata," Ann. 

 Myc, 12, 369-392, pis. 17-19, 1914. 



42 Hoffmann, H., " Die Pollinarien und Spermatien von Agaricus," Bof. 

 Zeit., 14: 137-148; 153-163, pis. 5, 1856. 



