362 SMITH U'l'I.U'ATIDN OF THE THKoKY OF 



Humidity oi Atmosphere and (b) Intensity of Light. This 

 factor is also complex in that it varies with the general organi- 

 sation and habit of the plant. 



It must however be strongly insisted on, notwithstanding 

 the complexity of these factors, that if careful records are 

 taken of (1) Shade Temperature of Air, (2) Humidity of Air, 

 (3) Intensity of Light, (4)Temperature of Soil. (o)Rainfall ; and 

 if in addition the general organisation of the plant is carefully 

 noted, there should as a rule in the case of plants with reserve 

 food be no factor wanting for an elucidation of the problem 

 of growth. 



Rapidity of translocation of food supply might conceivably 

 be a limiting factor even when all the others were in excess, 

 but since rapidity of translocation depends to some extent 

 upon temperature a temperature which limits this will limit 

 growth generally and will come under the head of Temper- 

 ature effect. 



EXTENT OF APPLICATION OF THEORY. 

 If the above outline should furnish a basis for the expla- 

 nation of all cases of growth from large supplies of reserve 

 material it will clear up a very much wider field of facts than 

 has been generally realized especially with regard to growth 

 in the tropics. 



Sharp Bursts of Growth in Tropical Trees. 

 The general fact of alternating periods of growth and rest 

 in tropical trees has been often noticed. (See Schimper (10).) 

 Botanists in the tropics have been struck with the fact that 

 many Bpecies <>f trees put on new leaves, which are often 

 picuous by their bright colours, in bursts and not conti- 

 nuously. The occurrence <>f Large numbers of trees with new 

 ' - of different bright colours may in fact alter the appeal - 

 anoe of the Whole forest and has no) tailed to attract attention. 

 It doc not however seem to have been so clearly noticed what 



this implies n ith regard t<> the growth of the shoots in general. 



it ion- an- being carried out OH this point nou and will 



form the subject oi a Future paper, It may be stated here 



