_Galago_, Geoffr., Mag. Encycl., Ann. 2, i., p. 49 (1796).
The African Galagos are generally larger in size than the Madagascar
members of the group, and have the snout produced beyond the lower jaw.
Their ears are large, membranaceous, and have a very mobile contractile
hinder edge, the animal having the power of folding them up at will. The
eyes are also large and approximated; the fingers and toes very long and
slender, and the tail thick and bushy.
The skull presents a high, broad, and round brain-case, with a relatively
short facial region. The pre-maxillary bones are very much reduced, so that
the muzzle, measured from the anterior margin of the orbit forward, is
shorter than the longitudinal diameter of the orbits. The bony palate is
also relatively short. Compared with those of the Madagascar genera {39}the
orbits are, according to Dr. Forsyth Major, much broader vertically and
horizontally in the genus _Galago_. The squamosal region of the skull and
the outer portion of the ear-capsules (the periotic) are large and
inflated. The mandible (or lower jaw) has its lower hind edge, or angle,
produced backward.
The dentition of the Galagos presents several important characters. In
respect to their upper teeth, the incisors are small, equal, and have a
hind cusp on the cingulum. A distinct gap exists between the canine and the
pre-molar teeth. Of the pre-molars, the anterior one is canine-like, and is
equally distant from the canine and its own next neighbour. To the outside
it has one main cusp, and generally one minute supplementary cusp on each
side. The median pre-molar shows three cusps, and one strong inner front
cusp. The posterior pre-molar is always molar-like. It has one front
supplementary and two main cusps to the outside; and one front and one
supplementary hind cusp to the inside: it has also on the crown the oblique
ridge spoken of above.
The molars have a deep concavity on their hind border, due to the
development of the cingulum on the inner half only of that border of the
tooth; to the outside they present two main cusps (and often supplementary
minute fore and hind cusps); while to the inside they present two cusps,
and also an intermediate cusp in front between the two fore cusps; the
oblique ridge is also here present; the hindmost molar is three-cusped. The
five hind molars are, therefore, nearly equal in size. In the lower jaw the
pre-molars are complicated. The anterior and median are canine-like and
procumbent, with a cusped heel behind; the posterior is distinguished from
a molar only by the lesser size of its fore-part. The molars are also
complicated; the anterior and median are equal in size {40}and
four-cusped--the two front cusps (united by a ridge) are taller than the
two hind ones, and there is a minute cusp between the two hind cusps. The
posterior molar, though smaller than the others, is five-cusped. The
oblique ridge is not present in the lower molars.
The brain of the Galagos is narrower and shallower than that in the
_Lemurinæ_.
The female gives birth to two or three young at a time.
According to Dr. Forsyth Major, who has made the Lemuroidea a special
study, the smaller African Galagos have departed less from the primitive
Lemuroid type than the Madagascar genera, in which greater specialisation
has taken place.
The members of the genus _Galago_ are widely distributed on the African
continent, but are unknown in Madagascar. They range throughout the dense
forest regions, from Abyssinia in the north-east, to Senegambia in the
west, and southward as far as Natal and Mozambique.
Almost all the Galagos are nocturnal. They are chiefly arboreal, and when
they descend to the ground they advance by hops on their long hind-limbs.
They feed chiefly on fruits, insects, birds, and birds' eggs.