98 INTRODUCTION AND BREEDING OF FISH. 
Quatrefages *—is comparatively poor in marine vegetation, 
and in shell as well as in fin fish. The scarcity of fish in some 
of its gulfs is proverbial, and you may scrutinize long stretches 
of beach on its northern shores, after every south wind for a 
whole winter, without finding a dozen shelis to reward your 
search. But no one who has not looked down into tropical or 
subtropical seas can conceive the amazing wealth of the Red 
Sea in organic life. Its bottom is carpeted or paved with 
marine plants, with zodphytes and with shells, while its waters 
are teeming with infinitely varied forms of moving life. Most 
of its vegetables and its animals, no doubt, are confined by the 
laws of their organization to a warmer temperature than that of 
the Mediterranean, but among them there must be many whose 
habitat is of a wider range, many whose powers of accommo- 
dation would enable them to acclimate themselves in a colder 
ea. 
We may suppose the Jess numerous aquatic fauna and flora 
of the Mediterranean to be equally capable of climatic adapta- 
tion, and hence there will be a partial interchange of the 
organic population not already common to both seas. De- 
structive species, thus newly introduced, may diminish the 
numbers of their proper prey in either basin, and, on the other 
hand, the increased supply of appropriate food may greatly 
multiply the abundance of others, and at the same time add 
important contributions to the aliment of man in the countries 
bordering on the Mediterranean.+ 
Some accidental attraction not unfrequently induces fish to 
follow a vessel for days in succession, and they may thus be 
enticed into zones very distant from their native habitat. 
Several years ago, I was told at Constantinople, upon good 
authority, that a couple of fish, of a species wholly unknown to 
* Souvenirs Wun Naturaliste, i., pp. 204 et seqq. 
+ The dissolution of the salts in the bed of the Bitter Lakes impregnated the 
water admitted from the Red Sea so highly that for some time fish were not 
seen in that basin. The flow of the current through the canal has now re- 
duced the proportion of saline matter to five per cent., and late travellers 
speak of fish as abundant in its waters, 
ae 
