Amphicarpaa monoica. 281 



histological structure not distinguishable from type {a\ do 

 not seem to possess the same capacity for responding to 

 conditions suitable for germination if both sets arc planted 

 without filing. It may be that {b) requires a longer resting 

 period than (a). 



An interesting feature has been noticed in the behavior 

 of the cotyledons, of both terrestrial and aerial seeds, but 

 particularly the former. Normally these, as has been stated, 

 remain below the surface; if however, the seeds happen to 

 be in such position that the cotyledons are wholly or partly 

 exposed to the light, chlorophyll is developed with astonish- 

 ing rapidity. Nor does it seem that much light is required; 

 seeds which were germinated between layers of flannel, in 

 a deep box placed under the shelves near the floor of the 

 greenhouse showed this phenomenon well within three 

 weeks. Aerial and terrestrial seeds behaved similarly in 

 this respect. 



During the winter a plant raised from a terrestrial seed, 

 whose cotyledons remained half above the soil, attained 

 the height of two and a half feet, and produced numerous 

 legumes. The size of the cotyledons was but little reduced; 

 they were firm and not at all shriveled in appearance. The 

 exposed portion of the cotyledons was an intense dark green, 

 really deeper than that seen in the leaves : the subterranean 

 half was quite white ; a sharp demarcation showed plainly 

 how the seed had been placed. 



Sections through the very green portion showed chloro- 

 phyll granules, closely crowded around the cell walls ; 

 in the deeper tissue of each cotyledon, these granules were 

 seen, sparingly scattered. Still deeper, no granules were 

 found. The iodine test revealed the presence of the large 

 starch granules characteristic of the terrestrial seed. These 

 were most numerous in the colorless portion, but were not 

 by any means absent in other parts. In addition, minute 

 starch centres were detected in the chlorophyll granules 

 themselves. 



Seeds planted in normal position soon develop a small 



