FIRST PRIMARY IN CERTAIN PASSERINE BIRDS. 248 
loped wings of some species, in order to make quite certain of our 
fact before recording it. 
From several nests of Passer domesticus, all of which un- 
fortunately contained eggs only, one egg (incubated about nine 
days) contained a young bird from which a wing could be 
‘obtained. When placed under the microscope nine primaries 
were already commencing to appear from their follicles, but the 
first primary, the follicular depression of which was well defined, 
had not yet appeared. 
A few days later, several young Canaries, which died seven 
and nine days after leaving the egg, were found to have all ten 
primaries, with their coverts, perfectly clearly developed ; we were 
thus compelled to come to the conclusion that the accepted 
definition of these three families, F'ringillide, Motacillide, and 
Hirundinide should be modified, and that, instead of the state- 
ment that the first primary is absent, the following should be 
substituted :—“ The first primary is concealed within its coverts.” 
It seems to us that the only explanation of the supposition that 
no first primary existed, is that the student has in every instance 
removed the concealed primary when taking off the under wing- 
coverts to trace the origin of the quills. 
eo AN 
Yj MN \\ 
Wing of Sparrow ten days old, the primary coverts removed. Enlarged 
about one-third. 
R 2 
