No. 374.] PLANT MORPHOLOGY AND PHYSIOLOGY. 107 
species which had shown no germinations in the moist soil were not 
affected by this treatment. ‘These experiments will be repeated and 
extended before final publication. 
Pror. Gro. F. ATKINSON: Experiments on the Morphology of 
Arisema triphyllum. 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 nutri- 
ment. 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, large two-leaved female plants with large corms 
were selected at the time the rudiment of the flowers was formed. 
The corms were cut so as to remove all but a small portion in con- 
nection with the bud and then set out. By removal in this manner 
of the larger part of the stored food, the plants were changed to male. 
A collection of these plants was exhibited. 
Dr. W. F. Ganonc: Upon FPolyembryony and its Morphology in 
Opuntia vulgaris Mili. The author has found this species markedly 
polyembryonic, the polyembryony having a double morphological 
basis. One set of embryos comes from a mass of tissue which appears 
to develop from the fertilized egg cell, and others spring from the 
wall of the embryo sac and seem to arise from endosperm cells. If 
this be true, it is a mode of origin hitherto unknown. The literature 
of the subject was summarized, and some remarks given upon the 
significance of polyembryony. Many species of cactus were worked 
over (eighty or ninety), and no other cases observed. 
Dr. W. F. Ganonc: Contributions to the Morphology and Biology of 
the Cactacee. Part Il, The Comparative Morphology of the Embryos 
and Seedlings. The paper is a continuation of the author’s earlier 
studies upon this family. It describes and figures germinated 
embryos of most of the genera and the more important species, dis- 
cusses the germination and growth of the embryos, their form, size, 
and color factors, and the features they show of importance for the 
determination of the phylogeny of the genera, the development of the 
seedlings, and the unfolding of the peculiar morphological features 
of the adult plants. Contrary to Pfeifer, the morphology of the group 
is of systematic importance. A tree of descent was exhibited. Anha- 
lonium and some other genera were shown to belong with genera 
from which they have heretofore been widely separated. Many 
interesting drawings were exhibited. 
