26 ScJiively — Recent Observations on 



occurred under its ordinary conditions. The form of the 

 legume, the size and shape of the seed, and also the histolog- 

 ical peculiarities remained unaffected. 



To recapitulate — from the above statements, there seems 

 to exist a relationship between the age of the legume selected, 

 and the extent of modifications to be expected as a result 

 of the action of the changed conditions. Those legumes sub- 

 jected to new environmental conditions, while the tissues were 

 yet plastic though quite undifferentiated, responded readily in 

 all respects. The result was remarkable, both morphologically 

 and histologically, for the legume as well as its contents. When, 

 however, the legume was allowed to develop for a time under 

 its ordinary surroundings, then the changes were found to 

 vary in proportion to the state of development which had 

 been attained before the new conditions were given an oppor- 

 tunity to act. 



In this connection it may be well to point out that subter- 

 ranean flowers or their young legumes, if kept growing in the 

 air, will produce legumes with contents which are typically 

 aerial, but such pods are always small, and contain only one 

 seed. These statements are based upon experiments made 

 with certain shoots which grew from the axils of the simple 

 leaves (first pair of green leaves) of a plant. These shoots 

 normally trail on the surface of the ground, and give rise to 

 flowers which produce subterranean legumes. Certain of 

 them w^ere tied so that they were compelled to grow upward 

 to the height of four or five feet. Upon the secondar>' 

 branches which were thus forced to mature fruit above ground, 

 were borne legumes of the character described. 



These experiments are striking illustrations of the remark- 

 able influence exerted by environmental conditions upon por- 

 tions of Amphicar-pcza possessing absolutely the same structure 

 in the young state. When one is exposed to light, and the 

 other to darkness, totally different morphological results are 

 obtained. Doubtless there are other factors which are quite 



