208 Morphlology and Physiology of Areas of LaugerhanA
than in the first and that the areas are generally more nearly sphericaj
or oval than in certain of the other mammals observed, though many
of them are considerably elongated, as seen in Fig. 7, B. In Plate XIII,
Figs. I and 2 are reproduced wax reconstructions of two small areas
of Langerhans from the pancreas of an adult cat. These appear, as
a rule, unless the sinuses are distended with blood or injected, as nearly solid
masses of cells, most of the capillaries being entirely collapsed and seen only
as a line of endothelial cells. Especially on the surface are the vascular openings
small, so that the cellular elements much predominate. The varieties of cells
are in large part the same as those already described; the cells are arranged in
irregular masses and to some extent in bands consisting of a single or double
row of cells. While the arrangement is variable and all possible forms are seen,
it is not unusual to see the cords with the intervening sinusoids passing entirely
or nearly across the area. as seen to some extent in both A and B of Fig. 7.
·
B
Fig. 7, A and B. Central sections of two areas of Langerhans from pancreas of
cat. X 200.
A number of double injections of the pancreas of the cat were attempted
and while the results were not so successful as could be desired, in certamn
portions of the tissue the injection was such that arteries containing the red
granular mass could be found, by the side of which could be traced a vein con-
taining the blue gelatin mass and from there could be traced the principal
branches passing to a Langerhans area. Certain of the sections from this
tissue were cut relatively thick, so that one section would often contain the
whole or nearly the whole of some of the smaller areas, and thus it was possible