The hair is long, black or very dark auburn, wavy and sometimes curly, but never woolly, and the men have luxuriant beards and whiskers, often of an auburn tint, while the whole body inclines to hairiness.
The external unlikeness of the apes to man depends much on their hairiness, but this and some other characteristics have no great zoological value.
Here the younger brother impersonated the elder, and succeeded in deceiving his blind father by imitating the hairiness of his brother.
There are, however, certain botanical differences connected with the arrangement and hairiness of the leaves which separate the two species.
Other varieties are hirtum, distinguished by the hairiness of the leaves and branches, and purpureum, which has the leaves suffused with a dull purple tinge.