uj! LI 8 R A 

 STOMATA AND DROUGHT RESISTANCE INVI 



MEALIES. Vy^#ss 



By Horace Athelstan Wager, A.R.C.S. 



JV 



This investigation was undertaken on the suggestion of 

 Mr. J. Burtt-Davy, Government Botanist of the Transvaal, to 

 whom I am indebted for placing material at my disposal. The 

 object of the investigation was to obtain an insight into the 

 relationship, if any existed, between the number of stomata 

 preesnt in the leaves and the power for drought resistance. It 

 was also to find out if those species adapted for drought resis- 

 tance had assumed any xerophytic characters such as reduction 

 of stomata. thickening of cuticle, covering of hairs, etc. The 

 following notes with the appended table are the results obtained 

 in those species examined. The cuticle in those cases not 

 specially mentioned was about 5 microns thick on both surfaces. 



Silver King. Midrib strong; upper surface with few short 

 scattered white hairs; under surface and edge smooth. Cuticle 

 about 8 microns thick on both surfaces. 



North American. Midrib strong; upper surface slightly 

 hairy, with short white hairs ; under surface glabrous ; edge 

 ciliate. 



Iozca Silver Mine, Midrib not very strong; few very short 

 hairs on upper surface, under surface and edge smooth. 



Boone County. Midrib very strong; upper surface with 

 minute scattered hairs ; under surface and edge smooth. 



Improved Learning. Midrib strong; upper surface with 

 few scattered white hairs, under surface and edge smooth. 

 Cuticle hardly developed, but slightly thicker on upper surface. 



Potchcfstrocm Pearl Midrib fairly strong; upper surface 

 rough with many small hairs; under surface and edge smooth. 

 Cuticle, upper surface 8 microns, under surface 7 microns. 



Hickory King. Midrib not strong; upper surface with ver> 

 few scattered short hairs; under surface and edge smooth. 

 Cuticle, upper surface 3 microns, under surface 4 microns. 



Hildrcth Yellow Dent. Midrib strong; both surfaces and 

 edge smooth. Cuticle, both surfaces 3 microns. 



Farmers' Reliance. Midrib fairly strong; both surfaces 

 and edge smooth. 



North Dakota Golden. Midrib very strong; upper surface 

 with sparsely scattered long white hairs ; under surface and edge 

 smooth. 



Bloody Butcher. Midrib strong; both surfaces and edge 

 smooth. 



Queen of the Prairies. Midrib very strong; upper surface 

 with few fine white hairs ; under surface and edge smooth. 

 Cuticle, upper surface 5 microns, under surface 7 microns. 



Southern Horsetooth. Midrib fairly strong; both surface 

 and edge smooth. 



