142 THE PLANT WORLD 



which had remained attached to the plant, but was now hard 

 and dry weighed 262 grams, a loss of 91 per cent in weight. 

 The bulk of this was water, but no doubt there was consid- 

 erable weight of other materials. After the stalk starts to 

 elongate, probably the only source of food and in many cases 

 water too, is that stored in the lea\'es. The total amount 

 withdrawn from the leaves in a short time must be very con- 

 siderable, for in two months the stalk reached a height of 

 over 33 ft. with a spread of branches approximately 7 feet 

 wide. The diameter of the stem 5 ft. 6 in. from the ground is 

 TO in. There are 29 branches, having an average of 270 flow- 

 ers each, a total of 7250 flowers. These are large, averaging 

 3^/4 in. in length just before opening, and weighing four 

 to an ounce, making a total weight of flowers alone 

 of about 114 lbs. An apparently average branch was re- 

 moved and found to have a weight of 6 lbs. so that the aggre- 

 gate weight of flowers and branches amounts 174 lbs. An 

 estimate of the weight of the stem was obtained in this 

 way; a somewhat smaller flowering shoot had been blown 

 down by the wind, but too much scattered to secure the total 

 weight. A piece of the stalk of definite dimensions was 

 weighed and the mass obtained. The mass was .40 cubic 

 ft. and the weight 16 lbs. From the dimensions of the stem 

 of the plant in question, the mass is 8 cubic feet, and if its 

 relative weight is the same as the other, it would be 320 lbs., 

 making the total weight of the flowering shoot to be 494 lbs. 

 Of course, this is only approximate, but it is probably pretty 

 close to the real weight. 



The food material for this growth is as mentioned, 

 drawn entirely from that stored in the leaves for they soon 

 begin to wilt and it is not likely they do any significant amount 

 of synthetic work after that. As to the source of water, 

 the following observations may be of interest. On May 7th, 

 the soil in which the larger agave was growing was given 



