THE SALMON, THE TROUT, AND THE SHAD. 743 



color from the secretions of the " appendices^ these themselves being 

 filled with the same matter. Nearer to the anus, this mucus became 

 darker, and finally assumed a reddish-black color. In no part of the 

 whole digestive organ did I find anything which might lead to the 

 supposition that any solid food had been taken. Near the pylorus, I 

 found in one of the specimens several tapeworms {taenia) with their 

 heads sticking in the appendices. In the tissues surrounding all these 

 organs, but more especially in the pyloric cceca, I found a large number 

 of entozoa. 1 



I have continued these investigations during the months of September, 

 October, November, and December, and invariably with the same result. 



The digestive organs of Trutta trutta likewise showed the char- 

 acters detailed above. In both species, males as well as females, in 

 such as had already propagated their kind and likewise in such as 

 still contained roe or milt, the character of the stomach and intestine 

 was exactly the same as that of the first two specimens of Trutta salar 

 examined by me ; and I never found any food or anything which might 

 be considered as remnants of food. Three times I thought I had found 

 a fishbone, but a closer examination showed it to be particles of wood 

 or bast which had become enveloped in mucus, and stuck to the side of 

 the stomach or gut. The thick or corky cellulose had withstood the 

 digestive power, which, at any rate had been reduced to a minimum, 

 and no new food had been taken in through which these indigestible 

 particles could have been carried out. Up to the beginning of January, 

 1874, I thus examined stomachs of forty-four such spawn-salmon 

 { u Laichsahne v ) — Trutta salar and Trutta trutta — and never found any 

 food. I must here state expressly that these investigations were made 

 during the spawning-season proper of both species. 2 



In the following, only Trutta salar is spoken of, as Trutta trutta ascends 

 the Rhine for the purpose of spawning only till the beginning of Jan- 

 uary. From January on, salmon {Trutta salar) are but rarely caught 

 in the neighborhood of Bonn, while on the Lower Rhine (near Wesel) 

 many are caught about this season. In Wesel, I succeeded in obtaining 



1 Regarding these, as well as the entozoa which I found in those species of fish which 

 I examined, later — Trutta fario and Alausa vulgaris — see Gurlt's " Verzeichniss der 

 Thicre, bei welchen Entozoen gefunden worden sind " in Wiegmann'a "Archiv fur Natur- 

 geschichte," XI Jahrg., vol. i, 1845, p. 223. 



2 The spawning-season of the salmon extends, according to Valenciennes, (p. 179,) from 

 the end of May till the end of February ; according to Siebold, (p. £99,) from May till 

 November. According to the information which I gathered from experienced fisher- 

 men and my personal observations, a spawn-salmon is scarcely ever seen in the 

 Rhine before the end of August. Those which show themselves in the Rhine at an 

 earlier date do not ascend the river for the purpose of spawning. As I have never 

 seen a spawn-salmon after the 10th January, I feel justified in assuming that the 

 spawning-season proper extends from the beginning of September till the beginning 

 of January. This explains the fact that the season when the Dutch are not permitted 

 to fish for salmon lasts from September 15 till November 15. — (From information com- 

 municated by Mr. Lisner, a fish-merchant of Wesel.) 



