284 THE ZOOLOGIST. 
conditions. 4. That each bird has to separately acquire its experience, 
and well remembers what it has learned.” And that, therefore, on the 
whole, the theories of Bates and Wallace are supported by the facts 
detailed. 
Tue following extracts are from an excellent summary in the ‘ Globe ’:— 
“In his introduction to a Report just issued by the Scotch Fishery 
Board relating to investigations on the life-history of Salmon, Dr. D. Noel 
Paton (Superintendent of the Laboratory) states that the curious life-history 
of the Salmon has always been a subject of the deepest interest, not only 
to the zoologist and physiologist, but also to the sportsman and the 
fisherman. In spite of the most careful study by scientific investigators, 
the migrations of the Salmon, and the various changes in condition which 
it undergoes, are even now far from being fully understood, and the careless 
observations and foolish traditions of keepers, fishermen, and ghillies have 
only served to involve the matter in a deeper cloud of mystery. 
** (Juestions to be answered.— What force urges the fish to leave its rich 
feeding-ground in the sea? Is it necessary that it should enter fresh water 
in order to perform the act of reproduction? Does it require or procure 
any food during its sojourn in the river, and, if not, how is it able to main- 
tain life, and to construct its rapidly-growing genital organs? In the 
female the growth of these is enormous. In April or May the ovaries con- 
stitute only about 1.2 per cent. of the weight of the fishin November 
they are no less than 23.3 per cent. In a fish of 30 lbs. in the spring 
they weigh about 120 grms.—in November they weigh over 2000 grms. 
The increase in the testes in the male is not so marked, but is sufficiently 
striking. In April or May these organs are about 0.15 per cent. of the 
weight of the fish, while in November they are 3.3 per cent. From what 
are these structures formed? As they grow, the muscle, as is well known, 
undergoes marked and characteristic changes. Not only does it diminish 
in amount as the season advances, so that the fish which have been some 
time in the river become smaller in the shoulder and back, but it loses its 
rich, fatty character, while it becomes paler in colour. Are these changes 
in the muscle connected with the growth of the ovaries and testes? And 
if so, in what manner and to what extent? On the other hand, in fighting 
its way up rapids and over falls an enormous amount of muscular work is 
accomplished by the Salmon. Whence is the energy for this work 
obtained ? Are the changes in the muscle connected with the performance 
of this work, and if so, to what extent are these changes connected with 
the muscular work, and to what extent with the growth of the genitalia? 
Lastly, the question arises, to what extent do these changes in the muscle 
modify the value of the flesh as a food stuff? 
