OF FISHES IN GENERAL. 
27 
Upon the drying of thefe ponds, die, and are corrupted *. 
But, however diflicult thefe appearances may be to ex- 
plain or in whatever manner the fifties were introduced 
into thefe ponds, we muft conclude, that they were ori- 
ginally produced from the eggs of animals of their own 
kind •, becaufe the idea of fpontaneous generation is re- 
pugnant to every maXim of found philofophy f. 
Fifties, in general, are male and female ; the former 
poffeffing the milt, and the latter the rot. Some indi- 
viduals of the cod and fturgeon, are faid, indeed, to con- 
tain both. The fpawn of the greater number of hlhes 
is depofited in the faud or gravel ; and, in that date, it 
is probable, that the roe and milt are mixed together. 
Summer is the moll common time for the fpawnmg of 
fifties ; becaufe, at that feafon, the water is tepified by 
the beams of the fun, and therefore better fitted for 
quickening the eggs into life. It is probably for this 
reafon, that the herrings frequent the fhores of Britain, 
at the [pawning feafon ; there not being, in the unfathom- 
able depths of the ocean, a fufficient quantity of heat to 
hatch their eggs. When they have depofited their bur- 
dens, they return to their former flattens, and leave 
their infant progeny to Ihift for tliemfelves. 
The fpawn of different fifties continues in the ftate of 
eggs, fometimes for a longer, and fometimes a fliorter 
period. In general, however, this period is propor 
tioned to the fize< of the animal. In the falmon kind, 
the young animal continues in the form ot an egg, fiom 
the month of December till April, the young caip con 
-n „ tiii ues 
* Vide Lind, on hot climates, Part II f ■* * 
7 tinnjEus, omne animal ex ovo. 
