Ix Department of Plant Physiology. 



(c) A study of the fixation of nitrogen by fungi, especially by 

 those fungi which are in nature important in the conversion of 

 organic matter, has been continued ; and a special report upon this 

 work will soon be presented. 



(d) The stimulation work mentioned in my previous report has 

 been continued by laboratory experiments, but further field tests 

 will be necessary before this topic may be considered as satisfac- 

 torily developed for a preliminary report. 



(e) A special study has been made of the toxic action of certain 

 organic and inorganic compounds which may be present in the soil 

 and a particular efifort is being made to determine the comparative 

 action of such compounds in different textures of soil, and also 

 to test thoroughly the relative value of the ordinary laboratory 

 water cultures in indicating the probable toxic action under natural 

 conditions. 



(f) In order to avoid the water cultures in certain fundamental 

 work, tests of a large number of non-nutritious substrata are in 

 progress with the hope of improving the methods now in use. 



(g) The work in tannin fermentation of commercial products, 

 especially of tannin-containing gall nuts, will be complete within a 

 short time. 



(h) Certain physiological diseases of plants, notably the gum 

 diseases of drupaceous and citrus fruits, have been investigated, 

 and this will be a special topic of graduate work during 190^10. 



(i) Further material has been collected for studies on the 

 cytology of some hybrid agricultural plants. It is not to be ex- 

 pected that an immediate report may be made in this phase of the 

 investigations, since the Department is largely dependent upon the 

 Departments of Horticulture and Plant Breeding for the material 

 employed, and the amount of time required for such work demands 

 that a large part of the time of one assistant should be devoted to 

 it to secure its proper development. Histological problems with 

 respect to the development of some important plants have been 

 assigned to graduate students, and it is hoped that the development 

 of this work will facilitate more practical problems to which it 

 is fundamental. 



III. EXTENSION. 



The extension work has been necessarily confined to correspond- 

 ence and to cooperation with the Extension Office in the 

 College of Agriculture. It was anticipated that we would be able 

 to undertake during the "summer of 1909 some special extension 



