xv BREEDING 415 
offspring. Perhaps the more primitive form of parental fore- 
sight is exhibited by those Fishes which, like the females of the 
Salmonidae, make a furrow in the gravelly bottom of a running 
stream for the reception of the eggs, and then cover them over 
with a layer of gravel, or like the Siluroid Arius australis, of the 
Burnett river in Queensland, which deposits its eggs in circular 
excavations in the sandy bed of the river and covers them with 
layers of large stones. But in neither case does it appear that 
either the male or the female takes any further interest in the eggs 
or in the young when hatched. Without actual nest-building, 
or even the preparation of a place for their reception, the eggs 
may be protected in various ways by the male. The common 
British Gunnel or Butter-Fish (Pholis gunnellus) rolls its eggs 
Fic 256.—The Butter-Fish (Phol/s gunnellus) coiling round a mass of eggs. 
(From Cunningham, after Holt.) 
into a rounded inass by coiling its body round them, the male 
and female taking possession of them alternately. The little 
clumps of eggs are then deposited in holes made by the boring 
Molluse, Pholas. Some British Blennies attach their eges in a 
single layer to the sides of cavities in rocks, or between stones, 
where they are watched over by the male parent. The eggs of 
the Lump-Sucker (Cyclopterus lumpus) are attached im masses to 
rocks or to piles and guarded by the male, who aerates them by 
keeping up a flow of water over the spawn through the action 
of his pectoral fins. When hatched, the young fry cling to 
the body of their watchful parent by their suckers. A more 
decided approach to nest-building is exhibited by the Sand 
Goby (Gobius minutus). In this species the male scoops out 
the sand from beneath an empty shell, generally that of a 
Pecten, and the female deposits her adhesive eggs on the under 
