XIV.—CONTRIBUTIONS TO THE BIOLOGY OF THE RHINE 
SALMON.* 
By Dr. F. Mirscurer-Riscu. 
Professor of Physiology at Baset. 
[Reprint from the Swiss literary contributions to the International Fishery Exposi- 
tion at Berlin, 1880. |t 
The following description is based on various statistics and on— 
(1.) Measurements, weighings, and notices as to the external appear- 
ance of 1,933 Rhine salmon, taken between Basel and Laufenburg, and 
229 Lower Rhine salmon from Holland and Wesel, 2,162 fish in all; which 
obsefvations were continued without interruption from November, 1877, 
till the spring of 1880. 
(2.) Observations, weighings, microscopical, and also chemical inves- 
tigations relative to the condition of the muscles, intestines, and espe- 
cially of the growing sexual glands (made at all seasons of the year, 
during the years 1876-1880) of 97 male and 99 female salmon (196 in 
all); besides numerous observations—made for the sake of compari- 
son—on sea salmon. 
It is well known that the salmon caught in the Rhine at different sea- 
sons of the year vary greatly as to the looks and condition of the fiesh. 
In comparing, in December or January, a male salmon, the so-called 
winter salmon, with the well-known hook salmon—the former with its 
bright, bluish scales, its well-rounded body, its short nose (about 4 to 5 
per cent. of the whole length of the body, measured from the nostrils to 
the root of the tail), without the slightest trace of a hook and hardly dis- 
tinguishable from a female; the latter with its nose of twice the length, 
an entirely different physiognomy on the front part of the head, with its 
thick skin resembling in its red and black spots a tiger’s skin, made dark 
by the superabundant development of the epithelium, and with its flat 
body and thin flabby abdominal walls—it is difficult indeed to become 
convinced that these two fish are specimens of one and the same species. 
*Zur Lebensgeschichte des Rheinlachses im Rhein. Translated from the German by 
HERMAN JACOBSON. 
t Statistische und biologische Beitrige | zur Kenntniss | vom Leben des Rheinlachses, | unter 
Mitwirkung von | Herrn I’. W. Glaser, Sohn, | Fischermeister in Basel, | bearbeilet von | Dr. 
F’, Miescher-Riisch, | Prof. der Physiologie in Basel. | Separatabzug aus der schweizerischen 
Litteratur sammlung zur | internationalen Discherei-Ausstellung in Lerlin. 
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