President’s Address ]xxxill 
sticky material. The fruitlets of Boerhaavia pentandra are covered with 
sticky hairs, and the same is the case with the persistent calyx of 
Plumbago Capensis. The little capitulum of Staavia glutinosa is covered 
with glue, and when ripe easily adheres to passing bodies. The seeds 
of Pittosporum are embedded in viscid resin, and the berries of the many 
species of mistletoe, Viscum, and Loranthus, contain so much glue around 
the seed that birdlime can be made from them. It is often stated that 
these latter seeds must be eaten by birds and deposited by them before 
they can germinate, but that is not necessary. On the contrary, I have 
noticed that sometimes the seed adheres to the beak of the bird which 
eats the berry, and is then attached to a branch by the bird that tries to 
get rid of it. I found numerous seeds fixed to the under sides of the 
branches of an olive-tree, where they were just commencing to germinate. 
An agreeable contrast to the grapple plant and its like is formed by 
the very large number of plants which pay for the service rendered to 
them by animals. They enclose their seeds in eatable pulp, and render 
the fruits conspicuous and attractive by adorning them with bright 
colours. The pulp is generally sweet, and often agreeably scented. 
The seeds of such fruit are always hard and stony, and very well resist 
the action of the digestive fluids of the animals, as proved by many 
observations and experiments. I have studied the structure of the 
shells of many such seeds, and found them mostly to consist of scleren- 
chymatous cells, very similar in appearance to those shown by a 
section through a bone or tooth. 
When I first turned my attention to this subject, no exact experi- 
ments of this kind were recorded ; I found it necessary to arrange some 
myself. For this purpose I chose the common robin redbreast and 
elderberries, and ascertained that there was no difference in the germi- 
nating power of the seeds that came directly from the berries, and 
those that the bird had eaten.* Subsequently a large number of seeds 
and birds were experimented with by A. Kerner, who ascertained that 
all the stony seeds from pulpy or fleshy fruits germinated well after 
their passage through the birds. 
The South African farmer knows only too well how resistant the 
seeds of the prickly pear (Opuntia Tuna) are, the fruits of which are eaten 
by birds, baboons, and natives. The eradication of this pest would be 
a much simpler question if the seeds were not so well protected. I 
shall mention only some, for the list of plants with edible fruits is very 
long. Eatable berries occur, among others, on Mundtia spinosa (schild- 
pad besjes), Lyciwm, Asparagus, Cissus Capensis (wild grape), Uvaria 
Caffra, Aberia Caffra (Kei apple), Royena glabra, and Gardenia Roth- 
manna, the latter enclosing the soft pulp in a thick, leathery skin. 
* R. Marloth: Schutzmittel der Samen, in Engler, Botan. Jahrbiicher, 1883. 
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