772 Scott. — On the Flowers of Spar mannia africana , 
series of photographs taken could then be projected with 
the lantern on the screen, and the development of the inflor- 
escence, which in reality takes several months, could be 
watched in progress and could pass before the spectators 
on the screen in a few minutes, until the buds first shown 
had become fruits. 
The difficulty of trying this experiment was principally one 
of expense. 
Professor Pfeffer 1 , of Leipzig, has made many successful 
botanical demonstrations with a kinematograph and has de- 
vised a very perfect apparatus for class demonstration, but 
the expense of his apparatus (exclusive of the cost of his 
original experiments) is too great to make it possible for use 
by the private investigator ; one of the most serious items 
being the cost of production of each film, which amounts, 
Prof. Pfeffer tells me, to ninety marks (£4 ioj.), while the 
apparatus for taking the photographs cost £45 (exclusive 
of the kinematograph and lantern for demonstration). 
I at first experimented with a small film kinematograph, but 
the results were not satisfactory, as the machine was not suitable 
for making time exposures, and the makers were unwilling to 
help adapt their machine for scientific work. Also the life of the 
films when obtained was so short. The following experiments 
were made with a machine called the Kammatograph, in 
which the photographs are taken on a glass disc instead of on 
a film. In the use of this machine I have received every 
possible help from the inventor 2 of it, who has done his best 
to adapt it in every way for the work. 
A short description of the machine will first be necessary 
to those who have not seen it. A glass disc of 12 inches 
in diameter is suspended in a metal ring ; this disc is coated 
with a sensitive emulsion, and is in fact a large circular dry 
plate ready for use in photography, capable of taking 350 
photographs. (Half one of these plates, after the photographs 
have been taken on it, is shown in Fig. 65, PI. XXXIX.) 
1 Jahrbuch f. wiss. Bot., 1900, vol. xxxv, p. 38. 
2 Messrs. Kamm & Co., 27 Powell Street, E.C. 
