136 POPULAR SCIENCE MONTHLY. 



babe can suck — a reflex action; and Mr. Herbert Spencer describes all 

 instinct as 'compound reflex action'; but it seems to be well known 

 that if spoon-fed, and not put to the breast, it soon loses the power of 

 drawing milk. Similarly a chicken that has not heard the call of the 

 mother until eight or ten days old then hears it as if it heard it not. 

 I regret to find that on this point my notes are not so full as I could 

 wish, or as they might have been. There is, however, an account of 

 one chicken that could not be returned to the mother when ten days 

 old. The hen followed it, and tried to entice it in every way; still it 

 continually left her and ran to the house or to any person of whom it 

 caught sight. This it persisted in doing, though beaten back with a 

 small branch dozens of times, and indeed cruelly maltreated. It was 

 also placed under the mother at night, but it again left her in the morn- 

 ing. Something more curious, and of a different kind, came to light in 

 the case of three chickens that I kept hooded until nearly four days old 

 — a longer time than any I have yet spoken of. Each of these on being 

 unhooded evinced the greatest horror of me, dashing off in the opposite 

 direction whenever I sought to approach it. The table on which they 

 were unhooded stood before a window, and each in its turn beat against 

 the glass like a wild bird. One of them darted behind some books, and 

 squeezing itself into a corner, remained cowering for a length of time. 

 We might guess at the meaning of this strange and exceptional wild- 

 ness; but the odd fact is enough for my present purpose. Whatever 

 might have been the meaning of this marked change in their mental 

 constitution — had they been unhooded on the previous day they would 

 have run to me instead of from me — it could not have been the effect of 

 experience; it must have resulted wholly from changes in their own 

 organization. 



The only theory in explanation of the phenomena of instinct that 

 has an air of science about it, is Mr. Spencer's doctrine of Inherited 

 Acquisition. The laws of association explain our intellectual operations, 

 and enable us to understand how all our knowledge may be derived from 

 experience. A chicken comes on a bee, and imagining it has found a 

 dainty morsel, seizes the insect, but is stung, and suffers badly. Hence- 

 forth bees are avoided; they can be neither seen nor heard without a 

 shudder of fear. Now, if we can realize how such an association as 

 this — how what one individual learns by experience may, in any degree, 

 be transmitted to the progeny of that individual — we have a key to the 

 mystery of instinct. Instinct in the present generation is the product 

 of the accumulated experiences of past generations. The plausibility of 

 this hypothesis, however, is not appreciated by the majority of even the 

 educated portion of the community. But the reason is not far to seek. 

 Educated men, even materialists — their own positive statements to the 

 contrary notwithstanding — have not yet quite escaped from the habit 



