Trelease.] 
412 
[March 15, 
of the seveal stages of dichogamous flowers, according to the 
conditions under which they are observed, makes it unsafe to 
speak too positively in this case from a limited number of obser- 
vations, but the development of a considerable number of flowers 
was watched carefully in 1880 and 1881, and the fact of protogyny 
is certain. These were kept exposed to the light in the north 
window of a comfortably warm room. Their development here, 
under apparently identical conditions, was not uniform ; but as a 
rule the stigma became receptive about three days before the 
dehiscence of the first anther, while the second stamen did not 
become mature until a half-week later. In direct sunlight and 
warm weather the development would probably be more rapid. 
As has been demonstrated by repeated trial, a stigma which is 
pollinated as soon as it becomes receptive, has passed its j)rime 
before the first stamen reaches maturity ; consequently a stage 
may intervene in which the plant is out of flower so far as func- 
tional activity is concerned, although technically it is blooming. 
There is also the possibility that all pollen may be removed from 
the first stamen before the dehiscence of the second, in which case 
another interval of the same sort occurs. These breaks in the 
continuity of blooming are, perhaps, arguments in favor of the 
Linnaean view, which makes of the apparatus a spadiceous inflor- 
escence consisting of two staminate and one pistillate flower, each 
of a single organ. This view, formerly held by Hegelmaier (l), 1 
has been later renounced by him for the belief that it constitutes a 
single diandrous monogynous flower (2). Here, as in other flow- 
ers, there is the possibility that imperfect development of single 
parts may produce fallacious appearances. Rarely the pistil reaches 
a certain size and stops growing, in which case, after the maturation 
of the stamens, one might pronounce the flower protandrous ; sim- 
ilarly, the first stamen may be arrested, and a like fate frequently 
befalls the second stamen. In all of these cases of apparent 
irregular development that I have seen, I have failed to find that 
the retarded organ ever reached maturity. So far as the pistil 
1 Where references are made, as here, the first figure refers to the contribution simi- 
larly numbered under the author’s name, in the list at the end of this paper. Where 
a second figure is used it refers to the page. 
