STUDIES OF THE DEVELOPMENT OF THE PIPERACEAE 
II. The Structure and Seed-Development of Peperomia 
HISPIDULA^ 
Duncan S. Johnson. 
The following study is concerned with Peperomia hispidula A. 
Dietr. This species, which has one of the most peculiar types of 
embryo sac thus far discovered among angiosperms (Johnson 1907), 
also has a surprisingly simple vegetative structure, as will be briefly 
shown here. The whole development of the flower, embryo sac and 
seed of this Peperomia will be described in some detail in order that 
the development of other species, to be described later, may be com- 
pared with it and thus the variety of development found within the 
genus made evident. 
The material used in this investigation was gathered near the 
Tropical Station of the New York Botanical Garden, at Cinchona, 
Jamaica, during visits made to that island in 1903, 1906, and 1910. 
These visits were made possible by grants from the Botanical Society 
of America, from the Bache Fund, and from the Carnegie Institution 
of Washington. It is a pleasure to acknowledge here the aid received 
from these sources and also the courtesies extended by the New York 
Botanical Garden,'in the use of its Cinchona Station, and by the Depart- 
ment of Agriculture of Jamaica. M. Cassimir deCandolle is here 
thanked for determining the species of this and other Peperomias for 
the author. 
The flowers, fruits and vegetative structures of the plant were 
carefully fixed by the writer, in several mixtures of chromic and acetic 
acids, in Flemming's fluid, and, in the case of some older seeds, in a 
mixture of acetic acid and alcohol. The study of the preserved material 
has been carried on at the Johns Hopkins University and at the Harps- 
well Laboratory. 
We will, for the sake of clearness, arrange the presentation of the 
features to be discussed under the following heads: A. Habit and 
vegetative structure. B. Development of the spike and flower. 
^ Botanical contribution from the Johns Hopkins University No. 41. 
323 
