148 PROCEEDINGS OF THE ACADEMY OF [March, 



forms that became acclimatized to cooler conditions, though the 

 thermophilic bacteria of soils, manure heaps, etc., still grow and 

 multiply at a high temperature and may be direct descendants of 

 hot spring species. 



The spores and even at times the mature plants of some fungi, 

 mosses, ferns and selaginellas can resist prolonged exposure to 

 55°-70° C. without injury, while 100° C. may not destroy the 

 vitality of the spores. Experiment has equally shown that spores, 

 or cells, of some of the above can be exposed to from 75° C. to — 150° C. 

 without loss of germinating capacity. Amongst flowering plants, 

 seeds have been exposed to from — 75° C. down to — 200° C. without 

 injury, while many species of tropical desert regions and of sub-arctic 

 or arctic regions show a range of temperature resistance from 75° C. 

 down to —65° C. An abundant protoplasm and stored food, 

 enclosed by thick mucilaginous or cuticular walls that can act as 

 regulators to environal changes, are all-important cell factors in 

 ensuring continued protoplasmic existence. The relative water 

 content of the cell, and the composition of the protein substances 

 that are included, are probably the main factors in limiting proto- 

 plasmic resistance. 



William H. Dall, A.M., Sc.D.: Mollusk-fauna of Northwest 

 America.* (No abstract.) 



The meeting adjourned at 1 P.M. for luncheon, and was called to 

 order again by the President at 2.20 P.M. 



Henry G. Bryant: ".Government Agencies in the Advancement 

 of Geographical Knowledge in the United States." Illustrated 

 by maps and charts. 



Attention was drawn to the importance of agencies such as the 

 U. S. Coast and Geodetic Survey and the Geological Survey in 

 advancing geographical knowledge. While the picturesque aspect 

 of the subject represented by expeditions of exploration has received 

 attention, the quiet work of these organized forces of the govern- 

 ment is little known to the general public. In early days, the 

 Federal Government sent Lewis and Clark, Pike and Fremont to 

 investigate the western country. The work of these men and the 

 discovery of gold in California resulted in bringing about a fair 

 knowledge of the main physical features of the country by the 

 middle of the nineteenth century. 



The Coast Survey is the oldest bureau of applied science, and for 

 nearly a century has been engaged in surveying the coasts of the 

 United States. Its officials, co-operating with those of Canada, 

 are surveying the Alaska boundary, where conditions of unusual 

 hardship are encountered. The operations of this bureau have 

 included: A survey of the coast, deep-sea soundings, study of the 

 tides, and of the Gulf Stream, and of terrestrial magnetism. 



