FEEDING AND REARING FISHES. 
303 
and it must be admitted that to some extent tliis is so. But it is known that in pools 
where tlie natural food is necessarily of a minimum quantity (for if the pool is at all 
well stocked it can only be tliat introduced in almost microscopic particles by the 
inflowing water) a given number of trout would be outstripped in growth by half the 
number on the same rations per thousand lish. This has been ascribed to exercise, 
freedom of movement, a larger quantity of oxygen per lish, and various other causes. 
Other things being equal, it is certain that the temperature of the water and the 
proiiortion of the jiond or pool subject to renewal each minute, or hour, will be found 
controlling factors of no small consequence. Of course, tliese elements may be, and 
sometimes are, disregarded to the point of asphyxiation, but they are here mentioned 
only as they influence development and growth. Tt seems certain that trout raised in 
a high temiierature grow more rapidly than those living in colder waters, and it is 
more than probable that where the current is very swift too much aliment is demanded 
in the work of living. It is true that in the natural home of the trout many line tish 
are caught in the swiftest waters. Because primarily they are line lish they are able 
to stand the exertion and strain of living in tliis swift water; and so, being in position 
to catch and enjoy the abundance of natural food which the current washes down from 
the sources of the stream, they become the liner. Again I would warn the reader not 
to confound domesticated trout in pools with wild trout in mountain streams. Mr. 
Livingston Stone lays stress on cold, sunless water and close confinement as dwarfing 
influences on trout, and urges the desirability of an abundance of warm water, range, 
and ])lenty of space in growing large trout. 
The following notes on the feeding of other species of fish at Neosho may be of 
interest: 
Blacli Bass. — The black bass {j\lieyo 2 )terus salmoides) decline a vegetable diet in 
any form, and can not be made to eat it. When mush is sometimes mixed with a 
considerable quantity of liver they will take it in the mouth, but quickly spit it out. 
The same results have attended frequent trials with crackers, bakers’ bread, and dog- 
biscuit. Tliej^ seem averse to vegetable diet, no matter how well disguised with a 
mixture of meat. I have been unalile to induce them to take artificial food except 
liver, and it must be fresh and sweet. Of course, minnows or other fish have not been 
tried, the effort being to overcome their natural inclination to eat fish. When the 
liver, as it will occasionally in summer, liecomes the least bit tainted the bass refuse 
it. Sometimes they decline everything. This peculiarity of the bass is well known to 
anglers. * In the Neosho ])onds the liass i-arely eat on nasty, raw days, but on i)retty, 
clear days they follow one around the pond, seeming to beg for food. The food of the 
young bass was discussed in my paper. The Propagation of the Black Bass in Ponds, f 
The Rode Bass {Ainhloplites rapestris). — In the first efforts at Neosho to feed 
these fish a small quantity of liver was daily i)ut in their pond, but it is doubtful if 
they ever swallowed any of it. Sometimes they would pugnaciously dart out and 
take a small piece in the moutli, to immediately spit it out. Formerly every few days 
a small quantity of liver was put in their pond to assist in breeding the insect life 
which furnishes the largest and most acceptable part of their food. For two years 
past no artificial food has been exi)euded on the rock bass. Their pond, of only 9,000 
square feet water surtace, is well planted with Potamofieton and Blodea, on which the 
smaller Crustacea breed iu such quantities as to support from 10,000 to 12,000 rock 
* Book of tlie Black Bass, James A. Hensliall, p. 360. 
t U. S. F. C. Bulletin, 1893, pp. 229-236. 
