284
AUGUST EPPLE
4. CHOANICHTHYES
a. Dipnoi. The pancreas of Protopterus lies within the dorsal wall of
the gut just before its spiral portion (Laguesse, 1890; Oppel, 1900;
Broman, 1937). According to Leiner and Schmidt ( 1957) , it contains islets
with A, B, D, and C cells.
b. Crossopteygii. The pancreas of Latimeria was recently discovered
by Grossner (1968); it is a compact organ at the dorsal surface of the
spiral gut. The structure described as “pancreas” by Millot and Anthony
(1958) consists of adipose and hemopoietic tissue (Grossner, 1968; Epple,
19eS). The topography of the islet tissue resembles closely that of
the selachians: it occurs as a single epithelian layer along the outside of
ducts, or as small buds consisting of B cells. Also, A and D cells can be
identified, and two granular types of intertubular cells deserve further
studies.
5. ACTINOPTERYGII
Based on macroscopic observations, and in accordance with Stannius,
Legouis (1873) differentiates three types of pancreas among the teleosts.
A compact pancreas, similar to that in most other gnathostomes; a diffuse
pancreas, split into lobes that might extend to various sites of the body
cavity; and a disseminated pancreas, which is scattered in small portions
over the entire body cavity. As can be seen from a compilation by Oppel
(1900), there are various transitions between these types: Both a compact
and diffuse pancreas occur, for example, in Pburonectes, and a diffuse and
disseminated pancreas are both mentioned in Gadus and the Cyprinidue.
Intrahepatic and also intrasplenic pancreas can be found in various
species (cf. Oppel, 1900; Bargmann, 1939; and others). In some cases
intrasplenic and intrapancreatic ( cf. Bargmann, 1939) or even intraovarial
islets (Lepori, 19%) were observed. Apparently, the splitting of the
pancreas can be influenced by the degree of the development of the
adipose tissue ( Baron, 1934). Pathological enlargement of the adipose
tissue caused pancreas degeneration in hyperphagic carp ( Plehn, 1938).
a. Chondrostei. The pancreas of Acipenser corresponds either to the
“difFuse” or to the “disseminated” type (cf. Oppel, 1900, Siwe, 1926).
b. Holostei. The pancreas of the bowfin, Amia, is “disseminated” or
“diffuse,” and pancreas intrahepaticum is present ( cf. Oppell, 1900; Siwe,
19.28). No Brockmann bodies occur, and the islets resemble those of the
higher vertebrates ( McCormick, 1924; Siwe, 1926). The islet cytology
appears to be unknown. Recently, an unusual type of insulin was ex-
AUGUST EPPLE
4. CHOANICHTHYES
a. Dipnoi. The pancreas of Protopterus lies within the dorsal wall of
the gut just before its spiral portion (Laguesse, 1890; Oppel, 1900;
Broman, 1937). According to Leiner and Schmidt ( 1957) , it contains islets
with A, B, D, and C cells.
b. Crossopteygii. The pancreas of Latimeria was recently discovered
by Grossner (1968); it is a compact organ at the dorsal surface of the
spiral gut. The structure described as “pancreas” by Millot and Anthony
(1958) consists of adipose and hemopoietic tissue (Grossner, 1968; Epple,
19eS). The topography of the islet tissue resembles closely that of
the selachians: it occurs as a single epithelian layer along the outside of
ducts, or as small buds consisting of B cells. Also, A and D cells can be
identified, and two granular types of intertubular cells deserve further
studies.
5. ACTINOPTERYGII
Based on macroscopic observations, and in accordance with Stannius,
Legouis (1873) differentiates three types of pancreas among the teleosts.
A compact pancreas, similar to that in most other gnathostomes; a diffuse
pancreas, split into lobes that might extend to various sites of the body
cavity; and a disseminated pancreas, which is scattered in small portions
over the entire body cavity. As can be seen from a compilation by Oppel
(1900), there are various transitions between these types: Both a compact
and diffuse pancreas occur, for example, in Pburonectes, and a diffuse and
disseminated pancreas are both mentioned in Gadus and the Cyprinidue.
Intrahepatic and also intrasplenic pancreas can be found in various
species (cf. Oppel, 1900; Bargmann, 1939; and others). In some cases
intrasplenic and intrapancreatic ( cf. Bargmann, 1939) or even intraovarial
islets (Lepori, 19%) were observed. Apparently, the splitting of the
pancreas can be influenced by the degree of the development of the
adipose tissue ( Baron, 1934). Pathological enlargement of the adipose
tissue caused pancreas degeneration in hyperphagic carp ( Plehn, 1938).
a. Chondrostei. The pancreas of Acipenser corresponds either to the
“difFuse” or to the “disseminated” type (cf. Oppel, 1900, Siwe, 1926).
b. Holostei. The pancreas of the bowfin, Amia, is “disseminated” or
“diffuse,” and pancreas intrahepaticum is present ( cf. Oppell, 1900; Siwe,
19.28). No Brockmann bodies occur, and the islets resemble those of the
higher vertebrates ( McCormick, 1924; Siwe, 1926). The islet cytology
appears to be unknown. Recently, an unusual type of insulin was ex-