SALMONS. 
837 
In great rivers, such as the Rhine" and Loire 6 , at least- 
some Salmon ha-ve been observed to pass a whole year 
in fresh water under these circumstances. Neither the 
spawning dress nor any of the other external characters 
of sex — the most remarkable of them being a carti- 
laginous projection, turned upwards and recurved, which 
•appears at the point of the lower jaw in the males 
ready to spawn, and fits into a cavity in the upper 
jaw — is developed in such specimens. The Salmon 
which observers have traced in this condition for two 
spawning-seasons are consequently incapable of spawn- 
ing until two, or perhaps three years have intervened. 
In Sweden, to the best of our knowledge, no direct 
observations on this head have been recorded; but in 
the Dal Elf, especially at Elfkarleby, specimens called 
OJclor, with bright (blank) dress and undeveloped gene- 
rative organs, have long been known. These specimens 
are bright Gralax, resembling in coloration the Blank - 
lax, and in other parts of Norrland, where they are 
also found in the Gulf of Bothnia, they bear the names 
of Borting and Tajmen. In Lake Wetter they are re- 
presented by the so-called Silfverlax. From Lake We- 
ner Widegren c records the occurrence of “adult indi- 
viduals of Salmo solar which in autumn had neither 
matured roe nor ripe milt”. Thus we possess trust- 
worthy evidence from several parts of Sweden as well, 
to the effect that the Salmons do not invariably spawn 
every year, even if they remain in fresh water the 
whole time. Widegren remarks the same circumstance^ 
in the reproductive operations of the Charrs. 
Quite natural is the consequence that the Salmons 
require a long time to recover the losses which their 
frame has suffered in propagating their kind. These 
losses are so great that many, perhaps most, of the 
older specimens, especially the males, die of exhaustion. 
All their fat and the greater portion of their flesh have 
been consumed, partly as a source of nourishment dur- 
ing the period when the fish entirely abstains from 
food, partly in the ripening of the sexual organs. In 
England these fish are known as Kelts , on the River 
Nissa in Ha-lland they are called pejsor. Miesciier- 
Ruescii has shown 8 how the great lateral muscles of 
the body and the dermal muscles undergo a fatty de- 
generation and yield the greater part of their volume 
to develop the ovaries; and a comparison (fig. 209) 
between the conditions of the intestinal canal of a 
male salmon before and after the spawning, is a strik- 
ing illustration of the great changes which take place 
in the body, while the spawning-dress is in course of 
development. 
a b 
Fig. 209. Intestinal canal and testes of a Salmo salar before (a) 
and after ( h ) the latter have swollen to maturity. After Buckland. 
Both figures reduced, a from a clean run fish weighing 35 lbs. and 
taken in the Avon on the 14th of March, 1871; b from an unclean 
(breeding) Salmon weighing 13 lbs. and taken on the 19th of Janu- 
ary, 1871. os, oesophagus; i, intestine; p, pyloric appendages; m, 
testes. In a both the pyloric appendages and the intestine are em- 
bedded in fat, and the testes thin; in b the testes are distended, and 
both the pyloric appendages and the intestine are without adipose layers. 
Statements have been made, it is true, which appa- 
rently show that in the sea, at least under favourable 
circumstances, Salmon may gain in strength and fatness 
with astonishing rapidity. From experiments made in 
1855 at Stormontfield (a Salmon-breeding establishment 
on the Tay in Scotland) — as well as from still earlier 
experiments (1795Q in the River Berridale (Caithness) 
— - it was concluded that Salmon-fry which left the 
Tay at the end of May, weighing at most 57 grammes, 
a See Miescher-Ruesch, Statistische und biologische Beitrcige zur Kentniss vom Leben des Rheinlachses im Susswasser , Intern. Fischerei- 
Ausstellung in Berlin 1880: Catal. Schweiz, p. 170. 
b See Kunstler, Rech. s. la reproduction clu Saumon de la Dordogne, Congr. Intern, de Zoologie, Paris 1889, Compte-Rendu des 
Seances, p. 83. 
c Ofvers. Vet.-Akad. Forh. 1864, p. 294. 
d ibid., p. 295. 
e 1. c., pp. 186 etc. 
f Day, British and Irish Salmonidce, p. 93. 
