AXD THE BISTEIBUTION OF THE STOMATA. 11^ 



If we look at tlie Second Comparison, and compare again Class ^ 



"with -TT- or j5^?^o see the influence of bloom on the upper surface 



determining the distribution of the stomata; for 29 per cent, in 



have the upper stomata equal in number to, or more numerous 







B 



than, the lower stomata, as compared with 5 per cent, in 

 or per cent, in ^. 



To put it in another way. In Class jr 45 per cent. Imve some 



stomata on the upper surface; but only one ninth of these have 

 the number of upper stomata equal to or greater than the number 



of lower stomata. In Class ^ 62 per cent, have some stomata 



above, and nearly half of these have the upper stomata equal in 

 number to, or greater than, the number of the lower ones. 



Looking at the third Comparison, and comparing Class ^ with 



Class -^1 we see the same accumulation of stomata on the lower 



x> 



surface, especially when this surface is bloom-protected. Com- 

 paring Class -rr with Class -g-, we see that this tendency dis- 

 appears when bloom appears on the upper surface. Lastly, in 

 TT- we see accumuhition of stomata on the upper surface when 

 this is the onli/ surface which Is bloom-protected. 



T> 



The number of species in Class -^ is too few to draw any 



trustworthy conclusions from. The great tendency to accumu- 

 lation of stomata on the upper surface is remarkable, especially 

 when this fact is taken in connection with what we know of 



■r> 



Class -TT, where the upper surface is likewise bloom-protected, 



but where the tendency to accumulation on the upper surface is 

 much smaller. It is possible that the distribution of stomata is 



T> 



determined in this class ^ by some other circumstances, and that 



the development of bloom on the upper surface alone has followed 

 as protection to the pre-existing stomata; whereas, under other 

 circumstances, we might imagine bloom to be developed for some 

 other use, and then the distribution of stomata to be altered 



