210 1Morphology uî2l1 Physiology of Areas of Langer/tans
7. . 6 x .225 X .27 mm. .0097 c. mm .i6x .19 x .2 mm. .oo64 c. mm.
8. .19 x .20 x .265 mm. .oi c.mm .i2X .I4X .17mm. .oo 29c. mm.
9. .i8 X .22 X .225 mm. .oo8gc. mm. .I7 x .23 x .I mm. .oog59c. mm.
io0. .24 X .28 X .29 mm. .oI94 c. mm. .2x .2I x .I7 mm. .o0043 c. mm.
Average size .01o39 C. mm. Average size .0047 c. mm.
-..25 x .35 X .325 mm . ........... 0284 c. mm.
2. .23 X .24 X .225 mm . ...............oI24 c. mm.
3. 20 X .38 X .225 mm . . ......7................o I c. mm.
4, .23 X .33 x .225 mm . ..................o7 c. mm.
5 8 X .20x ..6 mm . ............. 0057 c. mm
6. .24 x .25 X .215 mm ................... ....oI29 c. mm.
7. 24 x .30 x .32 mm... .................. ...023 C. mm.
8. .7 X .23 x .275 mm ...................... . oio8c. mm.
9. .23 X .34 x .25 mm ...................... ..oI95 c. mm.
o. .I5 X .20 x .2T5 mm.... ...................oo65 c. mm.
Averagesizc o.oI53 c. mm.
In Series I of the table, the number of areas averaged 3} to each c. mm. of
the section, so that about TO of these sections was area tissue. In Series II,
the average number was only I .3 to each c. mm. of the section and hence only
about T~0o of this pancreas was island tissue. The average number of areas
in each sq.mm. of the adult pancreas (Series III) is I .5, making about T,
of the pancreas consist of insular tissue. My figures are slightly different
from those given by Opie, Laguesse, and others, since Laguesse finds that on
the average only T(0 of the human pancreas is island tissue. This can be ex-
plained only as an individual variation, since in the figures of the observers men-
tioned there is quite as marked a variation between any two cases. It is worth
noting that the average size in the adult is actually greater than in either of
the other cases, while in the four-year-old child it is greater than in the new-
born infant. This is quite different from the results frequently reported,
since it is usually stated that both the size and the number of islands of Lan-
gerhans diminish wvith age, being greatest in the foetus and new-born. In the
four-year-old child, however, the number in a sq. mm. was greater than in either
of the others, and the proportion of area to glandular tissue was much greater in
this than in either of the others.
The shape of these areas varies greatly, but is in the main ovoid, though the
contour is quite irregular. Something of the shape and general appearance
may be seen in Plate XIV, Figs. I and 2. Fig. I reproduces a wax reconstruction
of a fairly typical area from the adult human pancreas, while Fig. 2 is the nega-
tive of Fig. I, representing the strands of connective tissue with blood-vessels,
etc. Since there was some shrinkage of the epithelial cells, the strands are
relatively somewhat larger than they should be, but otherwise indicate the
arrangement of the blood-vessels in the larger and more complicated areas like
the human. Plate XV, Figs. I and 2, reproduce the interior view of the models
represented in Plate XIV. The looser and more open appearance of the central
portion of the areas is readily seen in these figures. It may also be seen that in
some regions two and in others three larger sinusoids run through the area in