Note on Falco sacer. 247 
falcons. The central tail feathers also are somewhat longer 
in proportion to those adjoining, and are more ‘pointed than 
in ordinary. 
There is a common belief that the Saker tends to assume a 
barred plumage like the Kestrel as the bird advances in 
years; in this state it has been sometimes regarded as a 
distinct species, and named JF. hendersoni. The present 
writer regards this phase of plumage as due, not to age, nor 
to individual variation, but to the effect of captivity upon 
the plumage. When not exposed to the bleaching action of 
the tropical sun, the contour feathers of the Saker retain the 
dark brown bars which characterise the newly-moulted 
condition, while in a wild state the whole feather bleaches 
down to a nearly uniform earthy grey. Sakers moulted 
in captivity are always more or less barred, while hardly 
any wild bird shows more than the faintest trace of such 
markings. 
XX. A Method of Injecting the Canal of Petit. By JAMES 
Muserove, M.D., Demonstrator of Anatomy, Edinburgh 
University. 
(Read 16th December 1891.) 
I wish to describe a method of injecting the Canal of 
Petit in the eye, which, for demonstration purposes, presents 
certain advantages over the methods usually employed for 
displaying this lymphatic space. Hitherto, it has been 
customary to show the canal either by making an antero- 
posterior section of the eyeball, or by inflating the canal with 
air, after its removal from the eye along with the lens and 
vitreous. The first method gives a very imperfect idea of 
the size and shape of the canal, and the method of inflating 
with air has the great disadvantage that the specimen can- 
not be preserved for any length of time. It therefore 
occurred to me to try another plan, or rather, to modify the 
second method, by injecting the canal with liquefied carmine- 
gelatine, which is solid at ordinary temperatures. The Canal 
