4 8 



moisture relations, particularly the capacity of roots and leaves 

 for water absorption, the capacity of leaves to avail themselves of 

 atmospheric humidity, and the behaviour of chloroplasts in dry 

 and in strongly illuminated leaves. Material preserved for a 

 study of the anatomy of the leaves promises to show some inter- 

 esting structures securing mechanical stability in these thin 

 organs. 



Notes were taken for the preparation of a descriptive account 

 of the vegetation, with a particular view to correlating differences 

 in various habitats with the ascertained differences in physical 

 factors prevailing there. Differences in physiographic situation 

 were found to be at the bottom of the differences in physical 

 factors, and to be of more importance than altitude (above 4,500 

 feet) in determining both the fioristic and vegetative character of 

 the forest. 



SOME DISEASES OF PALMS. 

 By E. J. Butler, M.B., F.L.S. 



Imperial Mycologist, Agricultural Research Institute, Pusa. 



Fungus diseases of palms are rare, a fortunate matter if we 

 consider the extraordinary value of these trees to the people of 

 tropical countries. A few have appeared in India in recent years, 

 each apparently confined to a particular part of the country and 

 while due to different causes, agreeing in their general effects. 



KOLE ROGA DISEASE OF BETEL PALMS. 



A disease of betel-nut palms (Areca Catechu) has been known in 

 the Malnad districts of Mysore particularly near Koppa for many 

 years. It is locally termed " kole roga" or black rot. Up to the 

 present it has not been found elsewhere and, as it does not appear 

 to have extended much during the time it has been observed, it is 

 probably favoured by the special climatic conditions of the locality 

 where it occurs. 



The first symptom of the disease appears at the time of flower- 

 ing. A number of the flowers fall without setting fruits, and their 

 stalks blacken and putrefy. The rot gradually extends along the 

 inflorescences and affects the stalks on which nuts are forming, 

 causing the latter to drop while immature. Very often the damage 

 does not stop here. The flower stalk arises from the axil of the 

 lowest leaf and, therefore, leads directly to the base of the swollen 

 green part at the top of the stem. This green portion consists of 

 a number of leaf sheaths, which clasp the young growing end of 

 the palm, forming a thick protective covering to the growing 

 point. The lowest of these sheaths becomes affected near the 

 point of origin of the flower stalk, and a patch of rot makes its 

 appearance at this point. The sheaths next underlying the first 

 are then attacked and, since the internal parts are softer than 

 those outside, the rot spreads with increasing rapidity as it ap- 

 proaches the apical bud. When the growing point in the centre 



*From " The Agricultural 'Journal of India," Vol. I., Part IV., Oct. 1906. 



