138 FisHeR: SEED DEVELOPMENT IN THE GENUS PEPEROMIA 
species of Peperomia, embryo sacs essentially similar to that of 
P. pellucida, and also discovered evanescent walls following the 
first and second nuclear divisions in the sac. Miss Stephens (70), 
in 1909, described sixteen-nucleate embryo sacs for three different 
genera of the Penaeaceae, a family not closely related to the 
Piperaceae or the Haloragidaceae. Modilewski (50 and 52), in 
1909 and 1911, found sixteen-nucleate sacs in two species of the 
Euphorbiaceae, which again are not closely related to any 
family in which this type of embryo sac had hitherto been found. 
Johnson (35), in 1910, reported a typical eight-nucleate sac in 
another species of Piper. Samuels (59), in 1912, extended the 
work of Schnegg and of Ernst on the genus Gunnera. 
Since 1899, sixteen-nucleate embryo sacs, in which the arrange- 
ment of nuclei differs considerably in the different species, have 
therefore been found to occur in at least a half-dozen genera, dis- 
tributed among four very distantly related families of Angiosperms. 
In pursuit of additional evidence upon the significance of the 
abnormal embryo sac in the genus Peperomia, a study of the 
development of several species, not hitherto investigated, was 
undertaken. The species studied were: P. reflexa A. Dietr., P. 
verticillata A. Dietr., P. scandens Ruiz & Pav., P. metallica Lind. 
& Rod., P. Fraseri, var. resediflora.C. DC., P. blanda HBK., P. 
galioides HBK., and P. Langsdorffit Miq. (?). 
Piper tuberculatum Jacq., an arborescent species belonging 
to a very closely related genus, was also examined. 
Most of the material used in this study was from Jamaican 
plants. It was in part collected from living plants in Jamaica,* 
and in part—the chief portion—from Jamaican plants growing 
in the greenhouse of The Johns Hopkins University at Homewood, 
which were brought back by The Johns Hopkins University 
Botanical Expedition of 1910. 
The plants of Peperomia scandens and Piper tuberculatum, 
from which flower-spikes were collected, were directly determined 
by sa - Casimir de ‘Canela frost Portions of the plants sent ase 
* The material was collected and fixed at Cinchona by Professor D. S. Johnson 
on visits made to Jamaica in 1903, 1906, and 1910. The expedition of 1903 was 
aided by a grant from the Botanical Society of America, that of 1906 from the Bache 
Fund, and that of 1910 from The Johns Hopkins University. 
