232 



glad to receive specimens of this plant since a monograph of this 

 group for Xorth America is in process of preparation. 



3. "Canadian Arctic. Mosses," by Mr. R. S. Williams. 



A list made by the speaker enumerates 68 species of mosses 

 collected by various members of the expedition sent out by the 

 Canadian Government, in connection with the Geological Survey 

 of Canada, to the northern coasts of Alaska and British Xorth 

 America in I9i3-'i6. The genus most largely represented is 

 Drepanocladus with 11 species, all sterile; next comes Bryum 

 with 9 species, 5 of which are fruiting: all the other genera, 35 

 in number, are represented by i or 2 species except Dicranupi, 

 of which there are 3, one of which, D. elongatiim, is in fruit. 



The greatest number of species (7) separated out from one 

 collection and growing more or less intimately associated , occurs 

 under no. 60, representing a piece of sod, some 4 by 6 inches on 

 the upper surface, cut out from the tundra on Barter Island, on 

 the coast of Arctic Alaska. The species, all sterile and men- 

 tioned in the order of their abundance, the commonest first, 

 are as follows: Catoscepium ntgrittim, Swartzia montana, Dre- 

 panocladus brevifolius, Bryum neodamense, Chrysohypnum stel- 

 latum, Encalypta hrevicoUa, and Drepanod-adus scorpioides. 

 Under no. 23, a small collection made 50 m.iles inland from Cam- 

 den Harbor, Alaska, the following were separated out: Bryum 

 pallescens, Leptohryum pyriforme, Mnium afp.ne, Drepanocladus 

 aduncus, and Rhyiidiiim rugosum, the Bryum and Leptohryum 

 bearing fruit. The specimens are sterile unless othersvise stated. 

 One species, Bryum nsodamense, found in Europe, from the 

 Pyrenees to the Arctic coast, does not seem to have been credited 

 before to America. Another, Drepanocladus brevifolius, has 

 been noted from Greenland only, while two others are described 

 as new. The region collected over extends from about 68° to 

 70° 35' X'. and from the northern Alaska coast eastward to about 

 long. 110° \V. 



4. "Types of Sterilit>' in the Radish," by Dr. A. B. Stout. 

 Dr. Stout exhibited living plants of cultivated races of the 



radish, illustrating three types of sterility as follows: (i) blasting 

 of flowers, (2) self- and cross-incompatibility, (3) embryo abor- 



