96 AMERICAN JOURNAL OF BOTANY [Vol. 10, 



Madras. If the monsoon rains fail, severe consequences follow. This is 

 what happened in 1899 and 1900. There was a phenomenal failure of the 

 rains over a large part of India during the 1899 monsoon (June to Septem- 

 ber). As a consequence, a disastrous drought prevailed in the early months 

 of 1900. Both immediately before and some time after this severe drought 

 large bamboo forests flowered in northern India. 



In the Indian Forester for 1899 there appears the following note (10, 

 p. 178): 



The flowering of Bambusa arundinacea is reported ... to be general this year in the 

 Angul Division 3 of the Bengal Presidence. 



The drought of 1899- 1900 above referred to could have had no effect 

 on the life of these bamboo forests, since the bamboos were in flower (in 

 April) before the failure of the monsoon rains (June to September), the 

 disastrous consequences of which could not have been felt by plants until 

 early 1900. In 1898, the year preceding the flowering of the bamboos in 

 the Angul District, the monsoon was normal — at Angul (41.29 inches) 

 slightly below the average (49.34 inches), and at Bissipara (58.49 inches) 

 somewhat above the average (55.07 inches). For the four preceding years 

 (1894-1897) the total annual rainfall in the Angul District was either just 

 at the average or considerably above average — never below. We cannot, 

 therefore, accredit the general flowering of Bambusa arundinacea in the 

 Angul District of India in 1899 to a drought. 



In the Indian Forester for 1901 (11, p. 126) is reported 



The flowering on a large scale of the ordinary bamboo (Dendrocalamus strictus). The 

 area over which the flowering extends is estimated at 1200 square miles, and in this area, 

 although a few clumps here and there have escaped, the phenomenon is universal. 



The flowering occurred in the Chanda District of the Central Provinces 

 of India. The rainfall data for 1900 from sixty-seven observation points 

 in the Central Provinces indicate that the monsoon of that year was all 

 that could be desired. For example, the total annual rainfall for forty-five 

 of the sixty-seven stations was, in 1900, above the annual normal (in several 

 instances nearly double the average annual precipitation). 



It would hardly seem necessary to go further back than the favorable 

 monsoon of 1900 in our investigation of meteorological conditions and of 

 their bearing on the flowering of the bamboo forests in the Central Provinces 

 of India in 1901. This statement is based on the assumption that the 

 visible effect of a climatic influence which is potent enough to affect the 

 physiological state of plants is likely to become evident within a year after 

 the climatic factor came into existence. To what extent such an assump- 

 tion is justifiable is an open question. Brandis (1, p. 14) believes "that 

 such stimulating conditions must act upon the plant at least a year before 

 the flowering actually takes place." Yet in the same article he refers to 



3 The official meteorological designation of the "Division" in which the Angul "Dis- 

 trict" occurs is the "Chota Nagpur Division" of the Bengal Presidency. 



