THE SENSE OF SMELL IN BIRDS 623 
turbinal. The structure of the olfactory epithelium has been 
most fully described by Schultze, though it has been studied by 
Exner and Disse. 
3. The olfactory nerves. The olfactory nerves of birds have 
been given very little attention except from the standpoint of 
their development in the chick. They have been figured in draw- 
ings of the internal anatomy of the head by Scarpa for a few species 
of birds. There are also a few figures by Gadow (’91), in Bronn’s 
Thier-Reich. 
A single pair of so-called olfactory nerves are generally recog- 
nized as connecting the olfactory epithelium with the brain. 
(A more appropriate term would be ‘olfactory root.’ See Edinger, 
08, p. 252.) However, in Apteryx, according to Owen, there are 
more than two. He says that ‘“‘the olfactory nerves perforate the 
anterior and inferior wall of the rhinencephalic chamber by several 
foramina, but are closely invested and united by the neurilemma, 
especially along their upper surfaces, so as to appear for an extent 
of eight or nine lines, each as one large olfactory nerve.’’ Parker 
(91, p. 107), says that ‘‘the numerous olfactory nerves are given 
off from the ventral and anterior surfaces of the rhinencephal.”’ 
The olfactory nerves of the vulture are stated by Owen (’66), to 
be larger relatively than those of the common turkey. They were 
found by Gage (’96) to be minute in the English or house sparrow. 
The writer unfortunately has not had access to some of the old 
works on bird anatomy which may have had accounts of olfac- 
tory nerves. 
The early development of these structures in birds has been 
studied by Cohn (’02), Disse (’96-’98) in the chick, goose, and 
duck, by Kolliker (90), Marshall (78), Preobraschensky (92), 
in the chick, and Belogowy (09), in the chick. 
C. Central olfactory apparatus 
1. The olfactory lobes. The olfactory bulbs of many verte- 
brates are represented in birds, according to Edinger, by a For- 
matio bulbaris which covers the olfactory lobes except on their 
eaudal dorsal borders. In the literature of bird brains, this com- 
