TRIPHYLLUM AND ARISAEMA DRACONTIUM 5 
Owing to the lack of time and material the developmeut of the 
corm of Spathyema within the seed could not be traced but an ex- 
amination of the literature of the subject brought out the fact 
that many aroids manifest a tendency to carry on the development 
of the plant as far as possible before actual germination, 7. ¢., 
emergence from the seed and development of assimilatory organs 
occurs, * 
SUMMARY 
The .seeds of the two species present only a few unimportant 
differences in shape. In histological structure they are similar. 
The embryos are comparatively small and are imbedded in a co- 
pious farinaceous endosperm. The only essential distinction be- 
tween them consists in the slightly greater amount of food material 
in the seed of A. Dracontium, the extra procambium strand of its 
cotyledon and the weaker development of procambium in the 
plumule of its resting embryo. The first stages of the germina- 
.tion of the two seeds are of the same character and consist in the 
emergence of the hypocotyl and stem-bud from the seed coats at 
the micropyle, by means of the elongation of the cotyledon. 
As the development of the seedlings proceeds, the production 
of roots and a plumule takes precedence in A. *riphyllum while in 
A. Dracontium the enlargement of the hypocotyl begins at once 
_and the growth of the root and plumule is retarded. This pre- 
cocious development of the corm often takes. place to such a de- 
gree as to entirely inhibit the production of a functional plumule. 
The same differences between the two species in regard to the 
fibrovascular development is exhibited by the seedlings as is dis- 
played by the resting embryo. The structure of the stem-bud 
which develops upon the corm during the first season’s growth 
is absolutely the same in both species. 
The seedling of 4. Dracontium is diverging from what seems to 
be the normal type of germination in Arisaema, i. ¢., the develop- 
ment of an assimilatory plumule and the production of ‘a corm by 
means of the product of the photosynthetic activity of this organ, 
and is tending to produce a corm without the aid of a plumule by 
the direct transfer of the food material of the endosperm to the 
———____. 
* Engler. Monographiae Phanerogamarum. Araceae, 11: 34, 35- 
Griffith. Trans. Linn. Soc. 20: 274-276. 1847. 
