VOL. vn.] PLUMAGES OF THE ROOK. 131 



growing contour feather with the plumule alongside it, 

 old and unshed ; yet the two are so close as to seem joined 

 together, like the two barrels of a gun. 



The skin of the chin is at first pink and soft, but soon 

 gets hard and whitish after most of the contour feathers 

 have moulted. The newly-grown, soft, degenerate con- 

 tour feathers and the old plumules and filoplumes 

 gradually wear down, but worn remnants of them are 

 always to be seen with a glass until the autumn- 

 moult. 



By the time the chin is half -moulted, the small feathers 

 and bristles on the bases of the lower mandibles begin to 

 fall out (Plate 5, Fig. 14), and the moult creeps up 

 to the region under the eyes and the lores, and 

 lastly the bristles on the fore-head and at the 

 base of the nostrils are lost (Plate 5, Fig. 15). In 

 all these regions the proximal feathers fall first, and 

 the last to be left are the bristles nearest to the nostrils 

 and in the distal portion of the lores, and occasionally 

 a few bristles remain here until the following moult. 

 Some of the papillse of these regions remain dormant 

 and a distinct cavity is left where a feather has fallen 

 out, but most produce " pins," which however grow only 

 a millimetre or two above the skin and, unlike those 

 on the chin, never appear to produce feathers, but 

 remain as smaU rounded knobs. 



The time at which this moult takes place no doubt 

 varies individually, but it seems a lengthy process, and 

 even at the beginning of June it is not complete in some 

 bhds, although by this time some primaries have dropped 

 and the second autumn-moult has then commenced. 



Note. — ^I have carefully examined the generative organs of all 

 the specimens in first summer-plumage (i.e. one year or a little more 

 old) and have not found any in a breeding condition. In the females 

 the ova were always massed and scarcely visible separately, and the 

 oviducts were invariably thin and straight throughout. The testes 

 of the males were larger than in winter, those of first-winter birds 

 measuring four or five millimetres and the largest of the first- summer 

 birds (March and April) ten millimetres in length ; but the testes of 

 adults in April measured from seventeen to twenty-one millimetres. 

 One female had a small incubating-patch, although the condition 



