ON THE RHINENCEPHALON OF DELPHINUS 
DELPHIS, L. 
WILLIAM H. F. ADDISON 
From the Neurological Institute, Frankfurt-am-Main, and the Anatomical Labora- 
tory, University of Pennsylvania, Philadelphia 
FIFTEEN FIGURES 
CONTENTS 
BME OUICELOINS (5:5 i eee hee ne iia a ss too, «Ne fhe aoe Had setts oat 497 
Eternal Sh iUcllOG. ois ae oe SMI Rs, ea 22. «3 15) ge re ais om ps A arcas naa 498 
Mamimalransrhinencephalontere.. oc ac 6. 3. cae oie nei entree 499 
External form of dolphin brain...... Cd's i) Sea ces tet Oa Sat eM he eee ae 505 
Pexterns lielingiery meciat.<! 25 ke esc 23s « . RRA bd we Pe ee 507 
iberwary centers and connectiGns. o.6. 22s; ... sees era cee acok dens dommes 510 
SAU TETET TE A OL ee ae No one SS... .,.° SS mei eee pi ie sate gee ian Ss 519 
iterate ku Cd atti cota eee ns. 6. Re Sota hc ee 521 
INTRODUCTION 
The brain of the common dolphin is characterized by the 
entire absence of the olfactory tracts and bulbs, and hence the 
dolphin is completely anosmatic. It was in 1878, that Broca 
first applied the terms osmatic and anosmatic to the Mammalia 
as a means of classifying them according to the relative state of 
development of their entire olfactory apparatus. In the group 
of anosmatic Mammalia he placed the Primates, Cetacea, and 
Carnivora pinnipedia; leaving all others in the osmatic group. 
Later Turner (90) made the subdivisions macrosmatic, micros- 
matic and anosmatic. In the macrosmatic forms he included 
the Ungulata proper, the Carnivora fissipedia, and, indeed, the 
majority of mammals. In the group of microsmatics, or those 
having the olfactory system relatively feeble, he placed the 
Carnivora pinnipedia, the whalebone whales, apes and man; 
while under the anosmatic group were placed the dolphins, and 
497 
