Freiburger historische Bestände - digital

Dr. Cunningham—Surface Anatomy of the Primate Cerebrum. 61

(hi.) Children 4 to 5 pears old.—Position of the parietooccipital fissure
determined six times—in four males and two females ; three times on
the right side, and three times on the left side.

In every case the fissure was in front of the lambda. Average index 4-5.

(iv.) First Year of Life.—Position of the fissure determined six times—
in one male, in five females; four times on the right side, and twice on the
left side.

Fissure in front of lambda, ... 5 times; index 5-7.
Fissure coinciding with lambda, . . Once (female ; left side).

(v.) Full-time foetuses.—Position of the fissure determined nine times; in
two females and seven males; six times on right side, three times on the
left side.

Fissure in front of lambda in every case. Average index 4.

(vi.) Foetuses, 7j> to months.—Position of fissure determined six times—
in four males and two females, twice on right side and four times on left
side.

Fissure in front of lambda in every case. Average index, 4-9.

(vii.) Foetuses from 6£ to 1\ months.—Position of the fissure determined
five times.

Fissure in front of lambda in every case. Average index 5-9 in front.

In the following Table I have given the average lambdo-parieto-
occipital indices which have been obtained for the different periods of
growth. In every case these indices indicate the relative distance of the
fissure in front of the lambda, because, although individual cases are met with
in which the fissure is placed behind this point on the cranial wall, and
other cases in which it coincides with it, the general average always shows
the fissure at a greater or less distance in front of the lambda. The number
of hemispheres examined under each group is stated in the preceding list,
and it is unnecessary therefore to repeat this item in the Table.