208 



A Microscopic Examination of Certain Drinking Waters. By George 

 J. Pierce, F. M. Andrews, and A. C. Life. 



The Effects of Drought Upon Certain Plants. — An Experimental Study. 

 By Clara Cunningham. 



Because of the general knowledge of the subject, and the great influence of 

 drought upon the economics of agriculturists and manufacturers, the following , 

 experiments were undertaken. 



The purpose of this paper is to show by results of experiments the efTects of 

 drought not only upon the general appearance of the plants studied, but more 

 especially upon the different tissues. 



The plants used for observation were grown under conditions favorable to 

 normal and healthy growth for three or four weeks or until the plants were large 

 enough to use for experiments ; then removed and subjected to drought. 



The simple apparatus used to give the favorable conditions in air and soil, 

 consisted, first, of a large glass box 3 ft. long, 2 ft. wide, and Ih ft. deep, and fit- 

 ted with a glass cover; second, a number of Erlenmeyer flasks fitted with perfor- 

 ated stoppers holding long glass tubes. These flasks were filled with water and 

 inverted so that the glass tubes dipped into shallow pans containing the plants in 

 flower pots. 



The plants used in the experiments were Oxalis, Canna, corn, common bean, 

 Castor bean and cucumber. In making the drawings the camera lucida was used. 



Two Oxalis plants were taken from the green house. These plants were of 

 ecjual size and uniform appearance. One of these plants was examined immedi- 

 ately, and one was placed in the dry air of the laboratory and a minimum amount 

 of moisture supplied to the roots. 



Comparing the two plants as regards general appearance, I noticed that the 

 oldest leaves of the plant subjected to drought soon grew yellow and dropped off. 

 The leaves just budding when brought into drought grew very slowly, and did 

 not expand properly, and presented a peculiarly twisted or folded surface. After 

 being subjected to drought five weeks the leaf stalks had grown in length only 

 three inches, were of an intense dark green color, and somewhat stiffened or 

 woody. Leaves' of plants subjected to drought also showed a tendency to earlier 

 acquire the xanthophyll than those of plants under normal conditions. The effect 



