40 ARISAEMA TRIPHYLLUM 
an extreme case with one well developed ovary, apparently with 
fertilized ovules, borne on a staminate spike near its base. It 
has been observed that when any considerable number of pistillate 
flowers are present, the thickened axis characteristic of the pis- 
tillate spike is evident. Usually all the flowers borne on mixed 
spikes are normal in form and functional development. Peculi- 
arities in form and position of staminate flowers are frequent 
enough for mention. The growth of such flowers on an extension 
of the spike axis as in PLATE 1, FIG. 22,isnot uncommon. A variable 
number of flowers may appear so, sometimes but two or three, 
and again enough to give the appearance of a staminate spike 
above the pistillate as in A. Dracontium and other aroids. In a 
few cases the staminate flowers are borne on long pedicels (PLATE 4, 
FIG. 59) and show peculiarities of structure. Those forms, along 
with others showing a tendency to bisexuality, are more fully 
discussed in the section dealing with teratology. 
It has been noted elsewhere that the number of leaves seems 
to depend upon age and the abundance of food, the older, well- 
nourished plants producing two leaves, the younger plants but . 
one. There seems to be no relation, however, between the leaf 
development and the sexuality of the plant, the ratio of pistillate 
and staminate spikes being about the same with plants bearing 
one leaf as with those bearing two. 
It has been generally recognized by leon that the sex of 
plants of A. triphyllum may change. The first published attempt 
to determine anything experimentally concerning this point was 
by Atkinson (1). A report of this work was given at the Ithaca 
meeting of the Society for Plant Morphology and Physiology 
(December 28-29, 1897). The published abstract is quoted here 
in full: 
“Female, male, and neuter plants, the history of which was 
known by growing them in pots for one season, were potted, some 
in rich soil and others in poor soil, the object being to change them 
from male to female, etc., by varying amounts of nutriment. 
Male plants in rich soil were in one year changed to female, and 
large neuter plants in rich soil were changed to female. 
“In a second series, two large two-leaved female plants, with 
large bulbs, were selected at the time the fundament of the flowers 
m 
Setas 
