356 JAMES ROLLIN SLONAKER 



There are no structuj-es on the Hds of the sparrow which 

 correspond to the ej^elashes in mammals. A narrow row of 

 very small feathers, or plumules (F), which overlap in a shingle- 

 like manner, lies just above the marginal folds of the upper lid. 

 It extends from about 1 mm. above the anterior canthus (Ac) to 

 the posterior canthus, where it is joined by a single row from 

 the lower lid. The row on the lower lid differs from that on 

 the upper in that the plumules are farther apart and are deflected 

 downward and backward so that they scarcely overlap. The 

 row on the upper lid lies closer to the marginal folds than does 

 the lower, and, in the region directly above the pupil, somewhat 

 overlaps them. The function of this upper row, I think, is to 

 protect the eye somewhat from the bright light which might 



Fig. 3 Drawing from life of the right eye of the sparrow, showing the thick- 

 ened convoluted margins of the lids and the shape of the interpalpebral space. 

 X 5. 



enter it from above. There is a narrow space devoid of feathers 

 just above this marginal row of plumules on the upper lid, and 

 above this bare area are the feathers covering the head. These 

 true feathers of the head overhang the eye so as to protect it 

 from the rays of light from above. Besides this marginal row 

 of plumules on the lower lid, there exist a few plumules scattered 

 over a more or less wide area, which conforms in shape and size 

 to the outline of the eye which lies under the skin. When the 

 eyes are wide open these bare areas are scarcely noticeable unless 

 one parts the feathers. When the lids are closed, however, they 

 become more conspicuous, and this is more noticeable on the 

 lower lid (figs. 2 and 9). When the lower lid is closed, its thin 

 and translucent appearance is noticed. The pupil and the iris 

 can be indistinctly seen through it. 



