105 



glabrous, azonate, whitish, often somewhat tinged with yellowish or 

 reddish-brown ; pores equal to or longer than the thickness of the 

 hymenophore, the mouths punctiform, light cinnamon-brown or dark- 

 brown ; spores pale, with a flesh-colored tint, .00035-0005 of an 

 inch long, about .0002 o&an inch broad. 



Var. typicus. Smaller, 6-9 lines in diameter, sessile, mouths of 

 the pores light cinnamon-brown. On Abies nigra. New York. 



Var. obiwlutus. {Polyporus obvolutus^ Berk. & Cke.) Larger, 10 

 -15 lines in diameter, sessile, mouths of the pores usually dark-brown. 

 On Pinus contorta^ etc., California. OnPinus rigida. New York. 



Var. Torreyi, Gerard, Ms. Larger, 10-15 I'l^^s in diameter, stip- 

 itate, mouths of the pores dark-brown. California, {Leqit John 



Torrey, M.D.) 



Charles H. Peck* 



Explanation of the figures. — Fig. i, the stipitate variety 

 Torreyi. of Polyporus volvatus^ Pk., natural size. Fig. 2, vertical 

 section of the same. Fig, 3, spores x 1000, seen in three positions. 



I 



84. Sexuality of Crok)n monanthogynum. — In 1878 I col- 

 lected a few seeds of Crofon jnonanthogynum^ which were sown in the 

 spring of 1879. These germinated in the spring of 1880, and are now 

 in flower. There are four plants. Two are wholly pistillate, and two 

 wholly staminate. So far as these four plants go, it would seem that 

 the species is dioecious and not monoecious as described in our ref- 

 erences. 



It is interesting to note that these male plants are not half the size 

 of the females, and this accords with similar facts in hemp, spinageand 

 others; and with the general views explained in my Salem^ and Troy 

 papers (American x\ssociation for the Advancement of Science) that 

 a greater vita],(nutritive) power is associated with the production of 

 female than of male flower?. It is not always, however, that the lower 

 power of nutrition is evidenced throughout the whole plant as illus- 

 trated in these instances. Often it is only on the weaker branches of 

 the same plant that the male flowers are borne— the ones the most 

 highly vitalized resulting in female flowers. 



Thomas Meehan. 



85. Similarity between the Characeae of America and Asia.— 



Prof. Asa Gray has well shown the similarity of the floras of the eastern 

 parts of the two- great continents in relation to other groups of 

 plants, and I now propose to show that this resemblance extends to 

 the Characeae, although as yet our acquaintance with the forms of 

 this order, both Asiatic and American, is comparatively slight. 



My knowledge of Eastern Characeae is obtained wholly from some 

 articles by the late Prof. A. Braun, in Linnaea, Vol. 17, Ser. i. Charae 

 Prcissianae, and in Vol. i of Hookers Journ. of Botany, 1847, Char- 

 aceae Indiae Orientalis ctinsularnm Maris Pacifici. The former arti- 

 cle treats of the Australian species ; the latter of those of India, Cey- 

 lon, the Sunda, Mariana and Sandwich Islands, and is of the greater 

 interest to us. In his preface Prof. Braun says : " It is remarkable 



