DEPARTMENT OF BOTANICAL RESEARCH. 65 



instance of the "wonderberry," one of the products of Mr. Burbank's breed- 

 ing operations, the hairs were found to be of the same type as Solanum 

 guinense, one of the parents, while the general appearance of the plant, 

 taking most of its characters into account, is much like that of Solanum 

 villosum, according to Mr. Burbank's report. 



COOPERATIVE ARRANGEMENTS. 



Some very profitable arrangements by which the facilities of the Depart- 

 ment have been placed at the disposal of investigators not on the staff are to 

 be reported. 



Observations at the geographically arranged series of atmometer stations 

 planned by Messrs. Livingston and Shreve have been continued by various 

 observers, and their unselfish application to the details has materially for- 

 warded the investigations described in the previous pages. 



The work of Dr. I. D. Cardiff, of Washburn College, Topeka, Kansas, on 

 certain forms of the walnut (Juglans nigra), suggestive of a hybridization 

 with the hickory, has been thought of such importance that assistance has 

 been given for the purpose of making observations of the habits of the living 

 trees in northern Indiana and Tennessee and securing material for exact 

 morphological studies. 



Mr.W. D. Hoyt, of Johns Hopkins University, has carried an investigation 

 of the rhythmic action of the seaweed Dictyota, in fruiting, to a stage where 

 it seems that this phenomenon may be made to yield evidence of value as to 

 the inheritance of an acquired character. 



The constitution of the water of the Salton Lake is undergoing progressive 

 modification with the age of the lake and with the decreasing depth. The 

 analyses of the water made by the cooperation of Dr. W. H. Ross and Prof. 

 R. H. Forbes, of the Agricultural Experiment Station, University of Arizona, 

 furnish data of the greatest value in various phases of the problems under 

 consideration, with respect to the revegetation of this basin. Dr. Ross has 

 also carried out a large number of accurate estimations of the salt-content 

 and acidity of plants used for experimental purposes in studies of the water- 

 balance and of the origination of parasitism. 



Professors F. E. Lloyd and J. E. Kirkwood spent a year in the service of 

 the Mexican Continental Rubber Company, being engaged in a study of the 

 culture and conservation of the Mexican desert rubber plant guayule {Par- 

 thenium argentatum Gray). The geographic distribution of this plant, the 

 fact that it belongs to a family in which, so far, it is the only species furnish- 

 ing rubber industrially, and the nature of the product, together with the 

 general features of its habit and growth, make it of great interest. In 

 accordance with a working plan agreed upon, Dr. Kirkwood spent from 

 November, 1908, to July, 1909, at the Desert Laboratory, completing germi- 

 nation tests and embryological studies, while Professor Lloyd gave attention 



