"We have gone at length into some of these matters, as thinking that they were not without all speculative interest, as we shall show by and by. The arguments of Fabricius are easily answered. For I admit that the chick produces sounds whilst it is still within the egg, and these perchance may even have something of the implorative in their nature: but it does not therefore follow that the shell is broken by the mother. Neither is the bill of the chick so soft, nor yet so far from the shell, that it cannot pierce through its prison walls, particularly when we see that the shell, for the reasons assigned, is extremely brittle. Neither does the chick always keep its head under its wing, so as to be thereby prevented from breaking the shell, but only when it sleeps or has died. For the creature wakes at intervals and scrapes, and kicks, and struggles, pressing against the shell, tearing the investing membranes and chirps (that this is done whilst petitioning for assistance I willingly concede), all of which things may readily be heard by any one who will use his ears. And the hen, listening attentively, when she hears the chirping deep within the egg, does not break the shell, but she turns the egg with her feet, and gives the chick within another and a more commodious position. But there is no occasion to suppose that the chick by his chirping informs his mother of the propriety of breaking the shell, or seeks deliverance from it; for very frequently for two days before the exclusion you may hear the chick chirping within the shell. Neither is the mother when she turns the egg looking for the proper place to break it; but as the child when uncomfortably laid in his cradle is restless and whimpers and cries, and his fond mother turns him this way and that, and rocks him till he is composed again, so does the hen when she hears the chick restless and chirping within the egg, and feels it, when hatched, moving uneasily about in the nest, immediately raise herself and observe that she is not pressing upon it with her weight, or keeping it too warm, or the like, and then with her bill and her feet she moves and turns the egg until the chick within is again at its ease and quiet." This extract shows that here, as in all Harvey's work there was a union of common sense, observation, and experiment which enabled him to overturn without any unkindly feeling the cherished teachings of his predecessors and contemporaries.