144? Remarks on Incubation. 



loosely put together, do not take any part of the lining or in- 

 side of them to cover their eggs when they leave their nests. 

 You may see these birds, from time to time, while on the nests, 

 stretching out their necks, and pulling towards them little bits 

 of grass and drifting sedges ; these they place all around them, 

 on the outer rim of the nest. They cover their eggs with 

 these materials when they leave the nest, and not with any 

 part of the lining. 



Now, if, as the Professor states, the carrion crow covers her 

 eggs when she leaves the nest, how is she to act ? Is she to 

 fly off to the rabbit and the ram, for a fresh supply of fur and 

 wool ? Or is she to have recourse to the lining of the nest, 

 which has been most beautifully formed and arranged with 

 nice art before she began to lay ? In this case she will be 

 driven to the necessity of undoing part of the lining every 

 time she leaves the nest, and on her return she must con- 

 trive to replace it before she gets upon her eggs ; for, after 

 she has once got upon them, you will see by the contour of 

 the nest that she can do little or nothing more to the lining 

 under her. On resuming her seat, she certainly does not 

 push the fur and wool (our carrions here never use rabbit's 

 fur), with which the Professor tells us she covers her eggs, 

 to the outer edge of the nest, as the waterfowl do the bits of 

 grass and sedges with which they cover their eggs ; because, 

 if this were the case, we should see these materials lying there 

 when we ascend the tree. Now, I always know to a certainty 

 that the carrion crow has forsaken her nest for ever, if I find, 

 on mounting up to it, that any part of the lining is displaced 

 and put on the outer rim. Some unlucky schoolboy or 

 other enemy has been there, and either robbed it of its trea- 

 sure, or done to it that by which the crow instinctively knows 

 that it is neither safe nor profitable to return to it. 



The real fact is, that the Professor's specious theory about 

 the carrion crow covering her eggs with rabbit's fur and 

 wool, for the same reason that the dabchick employs hay, 

 simply comes to this, viz. that the carrion crow never covers 

 her eggs at all, when she leaves the nest. 



Last year, I had fifteen carrion crows' nests in the park ; 

 some of them, by the by, upon very high trees. In the many 

 visits which I paid to these nests, I could never find the eggs 

 covered, though I looked pretty sharply after them, and 

 pretty often into them. 



Here I will stop for the present, and merely observe, that one 

 day, on looking into the new edition of Montagu^ and casting 

 my eye on that part of the Professor's "Plan of Study" where 

 he [p. xvii.] remarks that " most authors occasionally indulge 



