INSTITUTE AND COLLEGE, PUSA, FOR 1912-13. 65 



plants in various stages of " disease," but none of these 

 proved capable of reproducing it, As they were mostly 

 belonging to the class of weak parasites, capable of infect- 

 ing the host plant only when the latter has been weakened 

 by some other agency, it was concluded that the cause of 

 the trouble lies deeper. Since it is practically certain that 

 it is not mycological, the enquiry was abandoned, and a 

 note giving a summary of the work, and the reasons for 

 this step, was submitted to the Bihar Planters' Association, 

 and circulated amongst the members. 



Forest tree diseases. 



This section, as usual, assisted the Forest Department 

 in examining and reporting on specimens of fungus 

 diseases of forest trees, mostly received through the 

 Imperial Forest Botanist, As this is rather a specialised 

 branch of mycology and as the work of the section has 

 grown too much to allow of all enquiries being; dealt with 

 equally fully, arrangements were made with the Forest 

 Botanist, denning what assistance we were prepared to 

 give. Under present circumstances, it will not usually be 

 possible to undertake any definite research into the causes 

 of undescribed diseases of trees, but where the parasite is 

 already known, or is allied to known ones, assistance can 

 be given. The Forest Botanist was supplied with all the 

 information available in this section on the obscure " spike " 

 disease of sandal. 



Green parasites. 



Mr. Shaw continued his investigation of the flowering 

 plant Striga, which is parasitic on the roots of jowar, 

 sugarcane and other Graminew in India- He also took up 

 the study of an allied plant, Sopubia, which attacks several 

 cereals. When the work was commenced, little was known 

 regarding these interesting plants, but the result of work 

 on South African species of Striga has recently been pub- 

 lished. It is still necessary to compare the Indian species 



