Lydia M. Dewitt 219
pathetic ganglia and the related nerves and staining reaction
of their cells in ordinary dyes is not dissimilar. Because they
are found in embryonic life and appear larger and more numerous
in the embryo and new-born than in the adult, Gibbes, Harris
and Gow, and others, regarded them as embryonal remains.
Krause, Kûhne and Lea, Renaut, Sokoloff, Dieckhoff, Pischinger,
Pugnat, Mouret, and others basing their theory on the character
of the cells, regarded them as lymphoid structures. Dogiel and
Tschassownikow considered them as exhausted acini, or as Dogiel
states "todte Punkte" because he found no connection with
the duct and found fat globules in the cells.
Lewaschew, Laguesse, Mankowski, Statkewitsch, Pischinger,
Saviotti, Kollossow, and many others assert that the islands are
merely temporarily changed acini, which may change back into
pancreatic acini. The reasons for this view are well expressed
by Mankowski. He states that the number of islands increases
during the period of gland activity and diminishes during rest;
that the islands of Langerhans represent one of the morpho-
logical stages of activity of the pancreas. Every lobule of the
pancreas must, at the end of its period of active secretion, pass
into the "Stadium der Langerhans'schen Inseln," which rep-
resents the morphological phenomena of the greatest exhaustion
or the greatest activity. He also notes the occurrence in any one
section of various stages of transition between gland acini and
the insulæe. Finally Zunz, Ssobolew, von Ebner, Schultze, Jar-
otzky, Sauerbeck, Diamare, and probably the great majority
of the very reoent writers on the subject regard the islands as
independent organs, vascular glands, arising from the same
anlage as the pancreas, but having a different function,-the
elaboration of a secretion which is poured into the blood. This
theory is based partly upon clinical and partly upon experimental
data and will be considered more in detail later.
If perfectly fresh and well-fixed pancreas is examined, the cells
of the islands, with their relatively small nuclei and prominent
protoplasm and their arrangement into definite bands separated
by sinusoids, are sharply differentiated from adenoid tissue,
which can sometimes be seen in close proximity. The develop-