WHAT DO ANIMALS KNOW? 
we use the term; the young ostrich does it as well as 
the old. It is the inherited wisdoin of the race, or 
instinct. 
A sitting bird or fowl turns its eggs at regular 
intervals, which has the effect of keeping the yolk 
from sticking to the shell. Is this act the result of 
knowledge or of experience? It is again the result 
of that untaught knowledge called instinct. Some 
kinds of eggs hatch in two weeks, some in three, 
others in four. The mother bird has no knowledge 
of this period. It is not important that she should 
have. If the eggs are addled or sterile, she will often 
continue to sit beyond the normal period. If the 
continuance of the species depended upon her know- 
ing the exact time required to hatch her eggs, as it 
depends upon her having the incubating fever, of 
course she would know exactly, and would never sit 
beyond the required period. 
But what shall we say of Mrs. Annie Martin’s 
story, in her “Home Life on an Ostrich Farm,” of 
the white-necked African crow that, in order to feast 
upon the eggs of the ostrich, carries a stone high 
in the air above them and breaks them by letting it 
fall? This looks like reason, a knowledge of the rela- 
tion of cause and effect. Mrs. Martin says the crows 
break tortoise-shells in the same way, and have I not 
heard of our own crows and gulls carrying clams 
and crabs into the air and dropping them upon the 
rocks ? 
135 
