. 1 and the Use of the Kinematograph . 763 
every day and night, and from these data the following results 
were obtained : 
The inflorescence is an umbel. At first the buds hang all 
on one side of the main peduncle, both buds and pedicels are 
densely hairy. The pedicel of each bud is jointed. This 
curious joint or pulvinus is situated at an average distance of 
about 1 cm. from the bud, and will be found to be much 
swollen on the side away from the bud. The swelling 
becomes more noticeable as the bud grows older and the 
functions of the joint come into play. 
This joint, which is present in all three species of Spar- 
mannia , bears in its action and structure some resemblance to 
the pulvinus found on such leaves as those of the sensitive 
plant ( Mimosa pudica ), and helps to regulate the position of the 
bud, flower or fruit at different times of its development. It 
is capable of causing the most delicate movements of the bud 
or flower, and responds readily to the stimulus of light. 
The greenhouse plant is specially favourable for the study of 
the joint. Owing to the fact that Sparmannia africana is 
used as a winter flowerer here, the flowers open much less 
readily than they do in their natural state. This can be 
easily seen, if a dried wild specimen be compared with 
one from a greenhouse. In the specimens in the Kew 
Herbarium one frequently finds flowers and ripe fruits of 
which some have already fallen on the same umbel, and very 
often (see PL XXXVII, Fig. 14) an umbel has nine or ten 
open flowers at a time, while in the greenhouse specimen quite 
frequently days pass without a fresh flower opening, while in 
one umbel drawn, the last flower lost its petals on March 19 
and the first fruit was not ripe till April 25. So that a joint, 
which under natural conditions might only be used for a few 
weeks, will in a greenhouse specimen have to remain active 
for as many months. 
Thus the joint develops by use, and, after a cold month, 
when the temperatures have been too low to admit of the 
flowers opening, becomes quite a conspicuous feature of the 
plant. 
