668 Campbell. — Studies on the Araceae . 
subsequent to fertilization, and much the same thing occurs 
in Spathicarpa , and probably in other Araceae as well. On 
the other hand, in Aglaonema commutation , it was often im- 
possible to demonstrate certainly the presence of any antipodal 
cells, although in the apparently closely related species, A. 
pictum , they seem to be always present. 
The development of the embryo in the two species under 
consideration does not show anything specially noteworthy. 
In Spathicarpa the embryo remains small, and there is a 
largely developed endosperm in the ripe seed ; in Aglaonema 
the mature embryo nearly fills the embryo-sac. 
The very considerable variation shown in the types of 
Araceae already studied make it highly desirable that as 
many types as possible should be investigated in order to 
determine the affinities of the family. It is to be hoped that 
the characteristic genera of the eastern United States may be 
examined by some of the botanists who are interested in the 
morphology of the embryo-sac, and have access to material 
of our native Araceae. 
Aglaonema. 
The genus Aglaonema 1 comprises about ten species of the 
East Indies and Malayan region. Several species, including 
A. commutatum , are in cultivation. The latter species was 
flowering freely at Kew in August, 1899, and apparently the 
same plant was collected at the Hope Gardens, near Kingston, 
Jamaica, in the summer of 1 897. A second species, A. pictum , 
was also flowering at Kew, and material of this species was 
collected. 
The flowers are unisexual, the pistillate flowers being borne 
at the base of the thick spadix, the crowded staminate ones 
occupying the upper portion. No perianth is developed, but 
there is a conspicuous white spathe, partially enwrapping the 
base of the spadix. 
The pistillate flower consists of a single carpel, with a 
1 Engler and Prantl, Die natiirlichen Pflanzenfamilien, n. Th., 3. Abth., p. 135. 
