O20" % R.. M. STRONG 
necessary, and the writer decided to study the problem by means 
of a labyrinth in which a demonstration of olfactory ability would 
require the association of an odor with the location of food. 
Such work was done mostly in the year 1907-8. 
During the autumn of 1909, the writer enjoyed the privilege 
of studying the unique collection of bird brain material in the 
Senckenbergisches Neurologisches Institut at Frankfurt am 
Main, Germany. Though a large number of bird brain sections 
representing a good many species of birds were studied, no new 
facts of importance concerning central olfactory relationships 
were discovered from them. On careful examination of the lit- 
erature it became apparent that there was need of a comparative 
study of the lobes and nerves, which could be done to advantage 
with the fine series of partly dissected heads in Professor Edinger’s 
collection. These were placed at my disposal for further dissec- 
tion and study. The nasal chambers also were studied. 
The writer wishes to express his hearty thanks to Prof. Dr. 
Ludwig Edinger, the director of the Institute, for the opportunities 
afforded and for his helpful interest. Thanks are also due to 
Dr. W. M. Cooper of Frankfurt, to Dr. Priemal, the director of 
the Frankfurt Zoologischer Garten, to Prof. John B. Watson of 
Johns Hopkins University, and to Mr. W. H. Osgood of the Field 
Columbian Museum of Chicago for additional material and for 
courtesies received. Through the kindness of Mr. Seth Smith 
and Mr. R. I. Pocock, the privilege of making a test of the olfac- 
tory sense in Apteryx was enjoyed at the London Zoological 
Gardens. Assistance in the preparation of the drawings was 
received from Mrs. Strong. 
2. LITERATURE 
A. General 
During the early part of the last century, a spirited controversy 
was waged by a number of naturalists over the question of the 
existence of an olfactory sense in birds. So much evidence on 
the negative side was brought forth as to put the general occur- 
ence of a sense of smell in birds in doubt ever since. 
