6 
Casey .4. Wood. 
At the inner canthus and especially on the lower lid the ciliary 
tufts are (to the number of 5 or 6) directed straight forward. 
Scattered over the two otherwise naked lids a varying number — • 
usually half a dozen — of plumules can generally be seen of the 
same size as those at the lid margins. Sometimes., though rarely, 
they form a regular second row of cilia along the margin of the lid. 
The eyelashes of Sparrow-like birds do not, judging from their 
position relative to the lid margins, act as a protection to the eye. 
An examination of them shows they are not prominent enough for 
this purpose ; they are too far removed from the interpalpebral 
space ; they do not overhang the lid margin, and they do not inter- 
lock when the eve is closed, as in many of the other vertebrates. 
They appear in bird life to occupy a place intermediate between 
the Ostrich, Seriema, and other birds that possess well-developed 
and useful eye protectors, and the Parrots that have none at all. 
Nevertheless the cilia of the Sparrow are more developed than 
in some other Birds, though less so than in the Ostrich, Seriema and 
the Birds of Prev. 
The eyelashes of most Birds do not take much if any part in the 
protection of the eyeball during sleep or on other occasions. The 
Sparrow does not entirely close his paired lids unless the cornea is 
touched with some blunt object, as a dissecting needle, although 
any approach of the object increases markedly the contractions of 
the nictitating muscles. 
Except during sleep, or in particular emergencies, the paired lids 
of Birds are rarely closed. Most of the ordinary functions of the 
human lid are performed by the nictitating membrane. The true 
lids of the Sparrow may indeed be regarded as accessory organs, 
whose functions are confined to the protection and moistening of 
the bird's eye only while he sleeps. The writer and Slonaker have 
not been able to observe the Sparrow with his third lid drawn over 
the globe (without closure of the paired lid margins) during som- 
nolent hours, as is said to be the case in some Birds of Prey, the 
Hen, etc. The soft sausage-like rolls of each lid-edge approach 
one another and close the interpalpebral space in a fashion entirely 
unlike the eyes of the higher vertebrates. However, even when the 
edge of the third lid is incompletely drawn over the globe the edges 
of both lids make slight but quite apparent efforts to close, as if 
there were slight contractions of the marginal fibres of the orbicu- 
laris. These winking efforts are more marked when the membrane 
sweeps entirely over the interpalpebral space; but in this consensual 
