RELATION OF TRANSPIRATION TO STOMATA 
any relation between the length or area of the pore of a stoma and the 
amount of water lost for the several species. 
Summary 
1. There was found no constant relation between the amount 
of water lost and the numbers of linear units of stomatal pore, i. e., 
the number of stomata per unit of leaf surface multiplied by the 
length of the average pore, in the various species studied. 
2. There is no relation between the amount of transpiration and 
the length of the pore of one stoma. The number of stomata per 
unit of leaf surface however varies at the same time that the length 
of the pore varies for the several species; so in this case we have two 
variables. 
3. There- is no relation between the amount of transpiration and 
the number of stomata per unit of leaf surface in the different species 
investigated. 
4. From the above results it would seem that the amount of 
transpiration is not governed entirely by stomatal regulation, and that 
the variations in the amount of water loss in different species cannot 
be accounted for by the size and number of stomata but must be 
explained perhaps by a complex of several factors. 
This investigation was suggested by and conducted under the 
direction of Professor Raymond J. Pool, of whose kindly advice and 
suggestions as well as the encouragement and suggestions of Dr. C. 
E. Bessey, I wish to express my sincere appreciation. 
University of Nebraska. 
LITERATURE CITED 
1. Briggs, L. J. and Shantz, H. L. The Wilting Coefficient for Different Plants 
and its Indirect Determination. U. S, Dept. Agr. Bur. PI. Ind. Bull. 230. 
1912. 
2. Brown, H. T. and Escombe, F. Nature 62: 212. 1900. 
3. Burgerstein, A. Die Transpiration der Pflanzen, Jena, 1904. 
4. Clapp, Grace Lucretia. A Quantitative Study of Transpiration. Bot. Gaz. 45: 
254-267. 1908. 
5. Eckerson, Sophia H. The Number and Size of Stomata. Bot. Gaz. 46: 221. 
1909. 
6. Freeman, Geo. P. A Method for the Determination of Transpiration in Plants. 
Bot. Gaz. 46: 118. 1909. 
7. Hales, Stephen. Statical Essays, Vol. I, London, 1727. 
