REPTILES, AMPHIBIANS, AND FISHES 37 



Japan, although it is not a very northerly form. The green toad, which reaches 



52° X. latitude in Siberia, but whose eastern boundary has not yet been fixed, is 



sometimes found in Mongolia; and the tree-frog, which inhabits Europe up to 



■58° N. latitude, is found right across the Asiatic continent. 



_ Of the fishes of Siberia it must suffice to state that these are in 



Fishes. 



the main specifically identical with those of northern Europe, the 



perch, carp, crucian carp, spiny loach, pike, salmon, and sea-trout, as well as many 



others, ranging into the Siberian rivers, which probably also harbour the lampern. 



Mention must, however, be made of the abundance of salmon of the genus 



Oncorhynchus in the rivers of Siberia and Kamchatka; the group being 



represented by several species, such as 0. orientalis, 0. lycaodon, 0. lagocrjilid/ns, 



•and 0. proteus. These arrive at the mouths of the rivers from May to Angusl : 



each species having its own particular time, which is wonderfully constant in spite 



of annual differences in the seasons. Although a few remain throughout the 



summer near the mouths of the rivers, and return to the sea in the autumn, 



practically the whole host ascend the rivers to spawn, after which they perish, in 



some cases actually choking the rivers with their bodies. It is these spawning and 



moribund salmon which form the prey of the Kamchatkan bears, to which reference 



is made above. Such a waste of life as occurs in the case of these salmon is very 



remarkable. 



