Amphicarpeea monoica. J53 



possesses .1 seed whose coat is delicate in structure 

 also that of the legume. No difficulty whatever is experi- 

 enced in germinating these, whether the entire legume is 

 used or the seed only. It is not yet known what function 

 may be exercised by the hairs of gland-like base peculiar 

 to this type of legume. These, as is surmised for the epi- 

 dermal structures of Arachis may assist in the accumula- 

 tion of nourishment. 



Thus these seeds, though resulting from the most reduced 

 type of flower, are those upon which the reproduction of 

 the species may be said to depend. As it has been proved ex- 

 perimentally that these flowers do not give rise to this vari- 

 ety of seed, if they remain unexposed to dark surroundings 

 or above ground, it seems almost useless to propose pro- 

 tection from destruction by animals as one reason for the 

 subterranean seed development. It is true animals do 

 seek them, but there would not exist these delicious 

 morsels, if the seeds matured under other influences. 



Darkness and moisture seem to exert some powerful in- 

 fluence upon these seeds, not only structurally, but also in 

 the nourishment stored up, and which possibly contains 

 certain substances valuable for the more successful growth 

 of the future seedling. Whether or not materials are ab- 

 sorbed from the surrounding soil, cannot now be answered. 

 Comparative chemical analyses of the aerial and subterra- 

 nean seeds will perhaps afford an explanation. 



The phenomenon of subterranean seed-production is one 

 that has never been satisfactorily explained. It is gener- 

 ally conceded that there must be some signal advantage to 

 the species. Amphicarpeea monoica is a plant whose flowers 

 at present illustrate transitional reduction. One is in- 

 clined to consider that the statement might be also made 

 for Trifolium subterraneum and Vicia amphicarpa. Was 

 Arachis hypogcea ever in the same condition? Amphicarpcsa 

 in some instances produces only the subterranean type of 

 legume. We have seen that the conversion of an aerial 

 to a terrestrial legume may be accomplished experimentally 



