Dr. Oscar Loew 45 
together with the swollen testa was easily 
separated from the seed. These seeds showed 
a pure red colouration on the outside, while 
the interior was violet, and no trace of brown 
colour appeared even after many hours’ ex- 
posure to the air, since the oxidizing enzyme 
(oxidase) had been killed, together with the 
living matter (the protoplasm of cells). 
The seeds commence to die when the entire 
fruit is kept for several days at 40° to 45° C., 
and the browning can be observed progressing 
from the surface of the seed toward the interior. 
By becoming over-ripe, the soft interior strata 
of the fruit shell, as well as the slime tissue 
around the seeds, contract more or less, and a 
hollow space is formed between the fruit shell 
and the seeds with their adhering slime tissue. 
Air diffuses into this space, and tne reason for 
the brown colour produced by oxidation within 
the fruit becomes apparent. During the fer- 
mentation process the browning does not often 
go farther than this, and the interior of the 
seed often continues to show the original violet 
colouration. It is then that the subsequent 
drying process, which admits air abundantly 
by diffusion through the testa, completely 
finishes the browning process. Some further 
darkening can take place during the roasting 
process when powdered cacao and chocolate 
are made from the fermented beans. 
The colour change of the cacao seed is 
no doubt similar to the colour change in the 
