75S 



SCIENCE. 



[N. S. Vol. XXII. No. 571. 



Colby M. Chester, U.S.N., superintendent U. S. 

 Naval Observatory. 



April 20. — ' The Protection of the United States 

 against Invasion by Disease,' by Dr. Walter Wy- 

 man, surgeon-general Marine Hospital Service. 



The Magazine. 

 The magazine of the society contains many 

 large colored maps. Four such maps were pub- 

 lished in the 1905 volume: (1) A chart of the 

 world, 25 X 45 inches, and in four colors, showing 

 all submarine cable systems and connections and 

 the steamship routes of the world; (2) a map of 

 northern Manchuria, in two colors, 18x44 inches; 

 (3) a map of the Philippines, in four colors, 

 23x36 inches; (4) a map of the Panama Canal 

 region, in five colors, 24 x 33 inches. The maga- 

 zine is very handsomely illustrated. All members 

 of the society receive the magazine free of charge. 



THE TORREY BOTANICAL CLUB. 



The meeting of October 10 was held at the 

 American Museum of Natural History, with 

 President Rusby in the chair and twenty-two 

 persons present. 



A letter was read from Mr. Edward W. 

 Berry, tendering his resignation as recording 

 secretary of the club, owing to his removal to 

 Baltimore. 



The announced program for the evening 

 consisted of informal reports on the summer's 

 work and observations. Several from whom 

 reports were expected were unable to be 

 present. 



Professor Francis E. Lloyd gave an account 

 of his summer's experiences at the Desert 

 Botanical Laboratory of the Carnegie Institu- 

 tion at Tucson, Arizona. On the way thither 

 a visit was made to the Tularosa Desert in 

 southern New Mexico. This desert is largely 

 an old lake bed of a comparatively recent 

 geological period. The moving white sands 

 which compose the desert overlie the mesa and 

 consist chiefly of gypsum, and a little below 

 the surface there is a considerable amount of 

 available water, which, however, is saline. 

 The vegetation of the region is peculiar, show- 

 ing various adaptations to the intense light. 

 Several interesting cases were observed show- 

 ing how yuccas and other plants are able by 

 continued vertical growth to keep their tops 



above the drifts of sand and how in the process 

 they help to build up and hold the dunes. 

 Rhus trilobata and also a shrubby labiate 

 form very marked pillar dunes. The gypsum 

 sand is partly soluble and it solidifies about 

 the vertically elongating roots and stems; 

 the outer parts of the dune may then erode 

 and be removed by the wind, leaving an iso- 

 lated pillar-like mass surmounted by the tops 

 of the living shrubs. An interesting and not 

 especially common plant of the region of 

 Tucson is Cereus Greggii, of a habit so pe- 

 culiar and aberrant that it does not seem to 

 be a Oereus at all. Like certain other desert 

 plants it has an underground storage system 

 which is very large in comparison with the 

 above-ground parts. The rapidity with which 

 foliage appears on desert plants after rains 

 has been often noted, and it has been a ques- 

 tion in how far growth of leaves may be stimu- 

 lated by the direct access of water to the- 

 above-ground parts without the intervention 

 of the root-system. This point was tested 

 during the past summer by experiments at the 

 Desert Botanical Laboratory. By means of 

 a siphon, water was supplied directly to the 

 leaf -buds and stems, in such a way as to pre- 

 vent the water from reaching the ground. It 

 was found that the desert plants thus stimu- 

 lated produce leaves in the course of a few 

 days. Very noticeable changes occur within 

 twenty-four hours, both when plants are stimu- 

 lated as described and after natural irrigation 

 by rains. Professor Lloyd further observed 

 diurnal nutations and nyctitropic movements 

 in an amaranth growing near the Desert Labo- 

 ratory. Photographs were shown illustrating 

 the observations commented upon. 



Dr. William A. Murrill spoke briefly of his 

 collections of fungi during the summer at 

 Ohio Pyle, Pa., in the District of Columbia 

 and in the Mt. Katahdin region of Maine, 

 describing also some of his camping experi- 

 ences in the Maine woods. Dr. Murrill was 

 impressed by the boreal character of the fleshy 

 fungi found about Mt. Katahdin, many of 

 them recalling species that he had collected 

 in Sweden. 



President Rusby reported on a Torrey Club 



