2ÔI 
lost if circumstances prevented the performance of the in 
stinctive act at a given period of growth and development ; 
just as the instinctive capacity of sucking is lost if it 
be not practised at a very early period. Nor is it difficult 
to conceive of the occurrence of such circumstances, for 
the nest of the wild duck is not always near the water, 
and hence we find that,— 
“When all the fertile eggs are hatched, her next care is to get the 
brood safely to the water. This when the distance is great neces 
sarily demands great caution, and so cunningly is it done that but few 
persons have encountered the mother and offspring as they make the 
dangerous journey. . . . Once arrived at the water, they are 
comparatively free from harm, though other perils present themselves 
from its inmates in the form of pike and other voracious fishes, which 
seize the ducklings as they disport in quest of insects on the surface, 
or dive beneath it. Throughout the summer the duck continues her 
care unremittingly, until the young are full grown and feathered.”— 
{Encyclopaedia Britannica, vol. vii., p. 506.) 
It is clear, then, that the facility with which a young 
duck takes to water has been greatly overrated ; and 
it is easy to understand how, in the absence of parental 
assistance, encouragement, and instruction, the aquatic bird 
might become a terrestrial one. This is a case in which 
there is not a senseless departure from a perfectly de 
veloped ancestral instinct—it is rather a case of an 
instinctive tendency which fails through want of the 
conditions necessary for its development—a possibility 
always liable to occur in the case of all animals born with 
imperfectly developed instincts. 
It is said that rabbits, in the island of Sor, have ceased 
to make burrows, but perhaps there is no mystery in this 
case if it resembles the one which Reclam has in view. 
“When rabbits for several generations have lived where they could 
not burrow, the descendants of these non-digging rabbits have lost 
the love or desire, formerly so strong in them, of digging holes.” 
— (Apud Büchner. Mind in Animals, p. 18.)