E. J. BUTLER 37 



lethargy of the cultivators, the difficulties of communications, and so on, can 

 have any doubt but that progress will be slow and that it ^\^ll be a labour of 

 the greatest magnitude to effect a general improvement. The work all 

 through has been hampered by the smallness of the trained stafE available, and 

 until this is remedied no adequate advance can be made. 



Summary. 



The work described above falls into three main divisions : A further 

 study of the life-history and activities of the parasite, Tylenchus angustus, 

 which causes the ufra disease of rice ; an attempt to explain the anomalies in 

 the behaviour of difEerent classes of cultivated paddies to the disease, which 

 were noticed in the earlier paper but which remained a complete puzzle until 

 the close relation between atmospheric humidity and the movements of the 

 worm on a dry surface was discovered ; and finally the application of the 

 facts ascertained to the control of the disease. 



PUSA, 



Jum 26, 1918. 



