Pomona College Journal op Economic Botany 417 



When the swelling of a fusiform trunk has attained a certain diameter, 

 it probably remains unchanged for the lifetime of the plant. I can, how- 

 ever, produce no personal observations on the subject. Certainly the same 

 cannot be asserted of the bulbous bases of some arecoid trunks, as those men- 

 tioned above, nor even of the entire lower portions of others of the cocoid 

 type, for in both eases an increase in diameter has been unquestionably ascer- 

 tained by numerous observers. I have myself perceived by careful measure- 

 ments the increase in bulk of the stem of a Jubaea spectabilis cultivated in 

 my garden near Florence. This I measured in the year 1906 on behalf of 

 Prof. Strasburger* and ascertained that it, at that time, was 3 m. 30 cm. in 

 girth at about 10 em. above the ground, whereas, in August, 1911, it had 

 increased to 3 m. 71 cm. 



In such a kind of trunk the augmentation in diameter may be cor- 

 rectly attributed, in a great measure at least, to a secondary merismatic 

 multiplication of the fundamental tissue; but still more, I think, to the 

 interlocation between the pre-existing elements, of a large number of fibro- 

 vascular bundles descending from the vegetative cone at every emission of 

 new leaves. 



spissiore et fluido scatet saccharino, quod sapore eum dulcissimo liquore Coci nuciferae 

 immo interdum cum succo expresso Arundinis sacchariferae potest comparari, atque a 

 venitoribus pro extinguenda siti bibitur. 



*Ueber die Verdickungsweise der Staemme von Palmen, in "Jahrbiich. fiir wiss. Bot." 

 XLIIL 4, page 607. 



