568 TELEOSTEI CHAP. 
adhesiveness, and the fact that the ova fall into the abdominal 
cavity, out of which they may easily be squeezed, renders artificial 
impregnation particularly easy, and the species of Salmo have 
always occupied the first place in the annals of fish-culture. 
Fertilised eggs are transported in ice, the development being 
simply suspended for several weeks, and several forms of British 
and American Salmonidae have thus been introduced into New 
Zealand and Tasmania, where some have thoroughly established 
themselves. 
The White-Fish, Coregonus, are more numerous in species than 
Salmo, and as a rule more readily defined. They are easily 
recognised by their large silvery scales and their smaller mouth 
without or with minute teeth. Some, like the Houting (C. 
oxyrhynchus) of Northern Europe, occur in the sea, entering 
3 nat. size. (After Valenciennes. ) 
rivers to spawn, whilst others, like the Sik, Weiss, Felchen, or 
Lavaret (C. lavaretus), are confined to lakes. British species are 
the Gwyniad (C. clupeoides), of Loch Lomond, Haweswater, Ulls- 
water, and Bala, the Vendace (C. vandesius), of Loch Maben, and 
the Pollan (C. pollan) of Lough Neagh in Ireland. 
The Grayling (Thymallus vulgaris or vexillifer), with its high 
dorsal fin formed of about 20 rays, one of the handsomest British 
fishes, inhabits the rivers and lakes of Northern and Central 
Europe, and is represented by a few allied species in Asia and 
North America. It derives its name from having the odour of 
thyme. 
The Smelt (Osmerus eperlanus) breeds in salt water, and 
although it often enters rivers, it does not ascend beyond tidal 
influence. The Capelin (MMallotus villosus), of the coasts of Arctic 
America and North-eastern Asia, deposits its eggs in the sand 
along the shores in incredible numbers, the beach becoming a 
