106 Alaskan Science Conference 



and Dr. George Llano of the Smithsonian Institution is en- 

 gaged in further researches. A very extensive study of the 

 known distribution of mosses in Alaska was prepared by one of 

 my students, Dr. A. M. Harvill, Jr., now at the University of 

 Alabama, but its very comprehensiveness has so far prevented 

 publication. The marine algae of Alaska have received some 

 attention, especially in Setchell's studies on Pacific algae, but 

 the fresh-water groups still remain relatively unknown. In my 

 opinion, there is urgent need for comprehensive reports on 

 each group of cryptogamic plants and for over-all studies on the 

 whole field of cryptogamic botany. As already pointed out, a 

 stock-taking or inventory of the flora is a basic research need, 

 not necessarily as an end in itself, but especially to give us a 

 knowledge of the materials available for research. 



Since my research interests center primarily about the bryo- 

 phytes, I will indicate some of the problems in which they 

 provide useful research material. Because of their relatively 

 small size and complete lack of roots, in a strict botanical sense, 

 mosses and liverworts are very directly affected by the sub- 

 stratum upon which they grow. Because of their sensitivity to 

 the nature of the substratum and to other factors of the physi- 

 cal environment, bryophytes are excellent indicators of these 

 factors. 



The recognition of this restriction of different species of 

 bryophytes to specific habitats and conditions enables us to 

 employ them in a very practical manner, although much serious 

 research is needed in this relatively unexplored field. Already, 

 however, we can say in a general way that the distribution of 

 mosses and hepatics, if properly interpreted, will give us much 

 information on extremes of soil temperature, soil texture, the 

 chemical and physical nature of soils, the nature and composi- 

 tion of rocks, and the water supply. Some species are restricted 

 to highly mineralized rocks, and careful research on this rela- 

 tionship might give practical results, since the members of the 

 genus Mielichhoferia seem to indicate the presence of copper 

 ion. The thick mats of mosses certainly influence the thermal 

 regime of the underlying soils and may be very important in 



