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plants of the forest. The mature leaves of this plant are 

 extremely variable in size, as for example 89 by 41 mm., 78 by 36, 

 52 by 34, 41 by 28. The appearance of inflorescences between 

 March 20 and April 2 in the axils of leaves below those being 

 measured invalidate to some extent the measurements after the 

 latter date. 



The most rapid growth observable in the rain forest is the 

 unfolding of the fronds of certain species of tree-ferns. The 

 presence of food reserves in the trunk places this phenomenon in 

 a different class from leaf elongation in the spermaphytic trees. 

 The following measurements on Cyathea pubescens, Mett. are for 

 consecutive fronds of the same individual. 



As noted above, all months of the year are favourable for 

 activity in the domains of growth and reproduction so far as 

 respects temperature and rainfall. To this fact is to be 

 attributed the general correspondence of the periodic phenomena 

 with those of tropical lowlands. The climate exhibits, however, 

 on closer examination several features which are inhibitory to 

 photosynthesis, — notably the high percentage of cloudiness and 

 the prevalence of fog, which cut down the light intensity, — -as 

 well as features which are inhibitory to transpiration, chiefly the 

 high humidity and the relative infrequency of direct insolation. I 

 take it that the slow rates of leaf growth observed are a cumula- 

 tive result in the activities of the plant of the combined condi- 

 tions unfavourable to photosynthesis and transpiration. 



In the grounds of Cinchona have been planted Liriodendron 



