4IO 



BOTANICAL GAZETTE 



[DECEMBER 



in depth, sealed and weighed on September 27. The water content 

 of the soil in the three containers was 13.8, 15, and 18 per cent 

 respectively. The wilting coefficient was 4.7. One of these plants 

 is shown in fig. 1 1 . 



The leaf area of, plant no. i was 0.3062 sq. dm. This was 

 determined by considering the leaves as having two flat surfaces 

 and multiplying the length of each by its average diameter. 



Transpiration losses are shown from September 27 to December 

 19 in fig. 10. During the period December 19 to February 11, the 

 total losses of two plants (the third having accidentally been 



Fig. 12. — Battery of five 3-year-old lodge pole pines and two 2-year-old yellow 

 pines; photographed February 28, 1918. • 



broken off) were 0.4 and i.i gm. respectively. On the basis of 

 the average daily loss, this is a mere fraction (only 1/146) of that 

 during the autumn period September 27 to October 10. In March 

 the plants were discarded because of the falling leaves; in fact, one 

 finally died, bat the others showed renewed growth in the spring. 



Pinus Murrayana 



Still another battery of needle-leaved plants, consisting of six 

 3-year-old lodge pole pines, was experimented upon during the 

 period beginning October 18. These plants, grown in containers 

 4 inches in diameter and 9 inches in depth, are shown in fig. 12. 

 The water content of the soil ranged from 16.4 to 21 .8 per cent. 



