ANATOMY AND HISTOLOGY OF THE ALIMENTARY TRACT OF 
THE KING SALMON. 
By CHARLES W. GREENE, Ph. D., 
Department of Physiology and Pharmacology, University of Missouri. 
INTRODUCTORY. 
In the older literature one finds discussions of the anatomy, histology, and embry- 
ology of a number of species of trout.® More recently a brief histological study was 
made by Gulland on the Atlantic salmon, Saltno salar.^ This study of normal structures 
is very brief and is given by the author incidental to the presentation of certain degen- 
erative changes in the digestive tract in the Scottish species. Gulland’s paper covers 
only about six pages of printed matter, including both the normal and pathological 
findings. Previous to the work of Gulland, Miescher published certain gross findings 
in the Rhine representative of the Atlantic salmon, but he does not offer histological 
details. 
No studies presenting the details of the anatomy and histology of the alimentary 
tract of the king salmon thus far have been published. In my studies on the function of 
the digestive tract of this salmon, and in similar studies of the changes that occur during 
the spawning migration of the species, it was found necessary to examine the normal 
structural characteristics of this interesting fish. The facts determined in these studies 
are set forth in the present paper. 
The digestive tract of the king salmon is, on the whole, quite similar in its gross 
anatomy to that of the Atlantic salmon, Salmo solar, and also is comparable to the 
anatomy of the species of trout. The alimentary canal of the king salmon has the 
relatively simple structure which characterizes carnivorous fishes in general. It consists 
of the usual parts, i. e., the mouth, esophagus, stomach, and intestine. Of special 
interest are the numerous diverticula of the small intestine attached to that limb of the 
intestine which immediately follows the stomach, and known as the pyloric cseca. 
Figure 3 presents a salmon in outline in which the anatomy of the alimentary tract is 
shown in its normal relations. 
The anatomy of the mouth is not presented in this paper. 
a Oppel, Albert: Mikroskopische Anatomic, bd. i, p. 28, 70, etc., bd. 2, p. 7, etc. 
1> Paton, D. No?l: Life history of the salmon. Article 3, by Gulland, “Minute structure of the digestive tract of the salmon, 
and the changes which occur in it in fresh water.” Report of the Fisheries Board for Scotland, 1898, p. 13. 
c Miescher, Friedrich: Statistische und Biologische BeitrSge zur Kenntniss vom leben des Rheinlachses im Siisswasser, 
Schweizerischer Fischerei-Ausstellung zu BerUn, 1880, p. 154. Also reprinted in Die Histochemischen und Physiologischen 
Arbeiten von Friedrich Miescher, 1897, p. 116. 
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