450 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [24] 
TABLE XI.—Average change of weight of male Rhine salmon, from summer till autumn, 
1878; two divisions of equal length, 79 fish in all. 
| 
| 
a oy oH | q SH | ey ~ lel ' 
lens z 2 - Sh ES Te £ S _|Daily decrease 
iS hae | 5 5 | ‘4 # _ ee of weight. 
Beer js 4 MS ee a Oe bei cio eel 
3 AS | Limitsof dates be-;, ¢ as ie Qe; 86 2 | S2 | Boe ; ales 
Sl 3“) 7 tween which the.|, Sle (SE) 9 [Fel ce | esel i) ates 
SWiaesee fish were caught. | 2s | At peal Weert) Seal | MONE des Pp Mey cite 
a nee ep one | & op en €° Esa | aPeS 
2 Sm oS | se | 2 R S Sof S a 
all 3 oe 3 5 g ago Ey ogs 
H| 8 > > | E Be & SSF pea Bes 
51 9 < q |% a | 1A AY G§ | ors 
i | = : | Ie | | . | 
ug_on= |§ June 4 to July 18..) June 26 } 22 | 850.4 | 9723 : 29 | § 106.95 | 2 
T..| 844-855 |} Tuty 22 to Nov. 4..| Sept. 15 | $819 |) 18 | s49.1| 9091 | § 2 |) 100. 00 | $ 7-80 | 9 858 
»9 ong |s dunel to Aug. 10..| July 41) 2 619 | 867.8 | 10657 | 2, 106.74 | 2. 
II.| 863-874 |} Sent. 5 to Nov. 4..| Oct. 4/$97)|} 20 | ses1| 9984 | § © | 2.100. 00 | 57-34 | 9-789 
| | | 
The average decrease of weight of the male fish would be still more 
striking if there did not arrive in the Upper Rhine (late in summer) a 
good many male stragglers, not quite as emaciated, and which some- 
what covered the decrease in older immigrants. But even in these fish 
a considerable decrease of albumen can be noticed in the muscle of the 
body. The flesh of two March salmon, caught near Basel, showed 17.9 
and 19 per cent. of albumen, just like the female fish of the same period ; 
a September salmon (caught September 19) which certainly belonged 
to alater batch of immigrants, and whose testicles were one-third formed, 
showed 16.6 per cent. albumen, and 25.7 per cent. dry substance. Three 
salmon of January, 1880, which had ejected their milt, showed (in 
their muscle) 13.0, 14.3, 13.3 per cent. albumen, respectively. The de- 
crease might, therefore, well be compared with that of the female fish ; 
possibly it was somewhat smaller. But, as the sexual glands need 
much less albumen for their growth than the ovaria, it seems that the 
male fish, corresponding to their greater animation and excitability, 
consume more albumen than the female fish. 
The influence—just referred to—of these stragglers .on the figures 
showing the degrees of emaciation makes itself felt with the female fish 
also, but at an earlier period. Whilst those groups which were com- 
posed of April and May salmon showed considerably greater average 
weights: than summer salmon of the same length, there was almost a 
stand-still in the average weights from June till the end of July or the 
beginning of August; in some groups there was even a slight increase 
(seemingly accidental); but from that time on a constant and consider- 
able increase was noticed. Infact there is among the salmon from these 
months—middle of July till beginning of August—a very distinct dif- 
ference between the older salmon (older as to the time of their arrival) 
and those recently arrived, such as is not found among early spring 
salmen. These last-mentioned fish have dark red and the former pale 
red flesh; the latter have considerable, and the former very little fat ; 
the duodenum of the latter is enveloped in fat, while that of the former 
shows but little fat. When the ovarium has reached one-fifth of its na- 
ture weight by far the larger mass of this fat has disappeared. This 
