GIANT BAMBOOS. 
259 
greater intensity of their growth. On the other hand in the 
giant bamboo,for which the intensity of growth is proverbial, 
a very marked sensitiveness was manifested to changes of 
moisture. The absence of a marked contraction when 
circumstances are adverse may however very well be due in 
the case of the bamboo to the greater vigour of its growth. 
Working with internodes of Phaseolus, Godlewski* found 
that a sudden decrease in the moisture of the surrounding 
air had a marked immediate effect upon elongation ; this 
was however quite temporary, hardly extending into a 
second half hour from the time of application of the 
stimulus. Thus a fall of saturation from 63 per cent, to 36 
per cent, was accompanied by a reduction in the half''hourly 
growth from *7 mm to *2 mm. And in the first few minutes 
there was even a slight shrinkage. 
My curves seem to show more agreement with Reinke’s 
“ acclimatization” result than with the extremely temporary 
effect which Godlewski obtained. Like Reinke’s curves they 
show a rate of growth actually proportional to the relative 
moisture of the air. 
One other more recent paper requires special mention 
here, namely that of F. Darwin, “ On the Growth of the Fruit 
of Cucurbita.”! Darwin found variations in the rate of 
growth of the fruit to be chiefly dependent upon the hygro¬ 
métrie condition of the atmosphere. In this case also 
increased dryness of the air was frequently accompanied by 
a diminution in size and weight. 
Here again we have a case which closely resembles the 
growth in thickness of Datura and the elongation of the 
halms of Dendrocalamus. So closely parallel do the cases 
appear to be that Darwin’s most general conclusions^ apply 
almost equally well to the results of my own observations 
upon the latter plant. 
* Emil. Godlewski. Studyja Nad WzrostemRoslin, Krakow, 1891, p, 73. 
German abstract. Anzeiger der. Akad. Wiss. in Krakau, 1890, p. 170. 
f Annals of Botany, Vol. VII., p. 459,1893. 
I 1, 4, 5, 6, 8, and 11 p. 485, loo. cit. 
