442 



SCIENCE 



[N. S. Vol. XXXIII. No. S47 



by chemical treatment of their seeds, and 

 on the influences of climate on plant organ- 

 isms. In collaboration with Professor 

 Ellsworth Huntington, research associate 

 of the department during a portion of the 

 year, the director has begun a general 

 climatological study of the region about 

 Tucson, giving special attention to the fac- 

 tors and effects of the Santa Cruz and 

 Asuncion river systems. 



Dr. Cannon, of the permanent depart- 

 mental staff, has given attention especially 

 to his elaborate investigation of the root 

 systems and habits of desert plants. For 

 the purpose of extending the range of his 

 studies in this fundamental subject he vis- 

 ited the Sahara Desert and will spend most 

 of the year in that advantageous field for 

 both comparative and direct observations. 

 Some of the more important conclusions 

 already established in respect to this in- 

 quiry are set forth in the director's current 

 report. 



Dr. Shreve, also of the permanent staff 

 of the department, while occupied with the 

 more general problem of the relation of 

 plants to climate in the United States, has 

 also carried on special investigations of the 

 vital statistics of plants in the vicinity of 

 the Desert Laboratory ; of the vegetation in 

 the Santa Catalina Mountains, and of the 

 physiological characteristics of the lace- 

 fern family of plants. In the first of these 

 researches he has been aided by the collab- 

 oration of Dr. Livingston, who resigned 

 from the staff of the department a year ago 

 to accept a professorship in Johns Hop- 

 kins University. 



Observations on the phenomena pre- 

 sented in the drying up of Sal ton Sea, and 

 especially on the influx of ve;^etation over 

 the bared strands and islands of this slowly 

 retreating body of water, have been con- 

 tinued during the year. In this work a 

 series of soil analyses of the strands has 



been secured through the cooperation of 

 Mr. B. E. Free, of the Bureau of Soils of 

 the U. S. Department of Agriculture. 



Publications by members of the depart- 

 ment issued during the year are shown in 

 the list on pages 32-33 and in the bibliog- 

 raphy of the "Year Book." Others in 

 press are Nos. 131, 139, 141. One of these. 

 No. 139, on the guayule, a desert rubber- 

 producing plant of considerable economic 

 importance, is the work of Professor Fran- 

 cis B. Lloyd, formerly a resident associate 

 of the department, but now a member of 

 the faculty of Alabama Polytechnic Insti- 

 tute. 



So many converging lines of fruitful re- 

 search are now being pursued by this de- 

 partment that it is difficult to summarize 

 fitly its current progress. This duty must 

 be accorded, in fact, as in all other cases, 

 to the director of the department con- 

 cerned, in his annual reports and in his 

 more detailed publications. From the ab- 

 stract scientific point of view the most in- 

 teresting feature of this work is found in 

 the introduction of statistical and other 

 quantitative methods, whereby biology is 

 now passing from the first to the next 

 higher stage in the development of a sci- 

 ence. From the more popular points of 

 view the work in question is of special in- 

 terest by reason of its bearing on the eco- 

 nomics of plant and animal breeding and 

 by reason of the light it is certain to shed 

 on the laws of human heredity. 



So large and so intricate a field of work 

 calls for varied objects and subjects of ex- 

 perimentation and for the resources of 

 many collateral sciences. Thus, studies of 

 heredity have developed the necessity of 

 certain investigations in physiological 

 chemistry, and a small equipment for this 

 purpose has been fitted up in a room of the 

 main laboratory building and put in charge 

 of Dr. R. A. Gortner. Similarly, for 



