214 Morphology anud Physiology of A teas of Langerhans
In birds, the areas of Langerhans have been found by Mouret,
Harris and Gow, Pugnat, Diamare, and others. Diamare
asserts that after careful study of numerous serial sections, he is
able to affirm that this structure in birds is entirely similar to
that in other vertebrates-"the islands consist of very vascular
epithelial cords." Pugnat studied the pancreas in many
species of birds, but described it especially in the dove. He
states that the pancreas consists of three lobes, each with a
distinct duct and that the cells do not form acini, but rather
a reticular structure like the liver. The islands, he states, are
large and irregular, consisting of small, elongated cells with indis-
tinct protoplasm and faintly staining nuclei. Both Mouret and
Pugnat regard them as lymphoid structures. I have examined
the areas of Langerhans in the dove and in the goose and found
them similar, but because of the greater distinctness of the
islands in my sections from the dove, my descriptions and figures
will be taken from this animal.
In the dove the two main lobes
of the pancreas are found in the
loop of the duod enum, one ventral
, and one dorsal and separated by the
mesentery. In the ventral lobe, the
;'- areas of Langerhans are few, small
and distinct. In the dorsal lobe, on
the other hand, they are large and
prominent. and it is from this lobe
"' '- ~ W that my figures are taken. The pan-
creas vas congested and all the
blood-vessels of the areas were filled
with blood and hence were very dis-
s ptinct. It is difficult, on account of
Fig.II.-Portion'the diffuse character of these areas,
to determine with any exactness
central ~ ~~their size or number. They are larger
and more numerous near the central
part of the lobe than at the periphery.
Fig. xi, a low-power drawing of a
small portion of this part of the dor-
Fig. i.sPortion of section through sal pancreas, may serve to show the
central part of dorsal pancreas of dove. size and irregularity of shape and .
X 50. apparent number of the islands in
this region.
Several of these, however, unite into one area in a latersection, so that the