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demand the adoption of a new habit as a condition of 
safety. It is a case of ending or mending, and of doing 
this not in the course of generations but at once, in the 
course of days and it may be of hours. 
A writer in Nature gives us an illustration of the 
sudden change of instinctive action on the part of 
the toad, of which the following is a summary :— 
“ It should be premised that when a toad is disturbed and jumps 
into the water, he makes a shallow dive, rises immediately to the sur 
face, swims upon it by a sweeping curve at once to the bank again 
and there it rests awhile before coming to the land. On the other 
hand, the frog when similarly disturbed makes a strong dive directly 
to the bottom upon which they lie prone, with the legs flexed against 
the body and into the mud of which they settle themselves a little. 
There they remain and exhaust the patience of one who may attempt 
to wait for them to rise. Some years ago the country immediately 
adjacent to the eastern base of the Rocky Mountains was changed 
by irrigation from a comparative desert into a veritable garden of 
Eden. Vegetation brought insects and the insects frogs and toads. 
The action of the settlers in regulating their irrigating ditches 
(especially if they had to keep them free from weeds) would have 
been fatal to the toad if he had maintained his customary mode of 
action, or even if he had slightly modified it; but in order to escape 
the new danger, he adopted a new method, and like the frog made 
a strong dive directly to the bottom.”—(C. A. White. Nature, 
vol. xvii., p. 248.) 
Thus it is obvious that the canon Natura non facit saltmn 
cannot be applied to this toad—he made a sudden leap 
from one method to another, and it was a leap for life. 
The following account of a modification in the art of 
nest-building may be cited as another proof of the occur 
rence of crises in which it was necessary that the 
intelligence should at once interpose to save the threatened 
life. Mr. W. Colton Oswell says:— 
“ The ornithological name of the bird I don’t know, but he’s some 
thing between a toucan and a hornbill—neither one nor the other— 
about the size of a large pigeon, though, if I remember right, more 
like a woodpecker in build. After marriage the birds select a hole in