Herrick, Surface Anatomy of the Btain of Birds. 173 



The olfactory lobes are not fused and project freely and 

 are large, even for a bird so low in the taxonomic series. The 

 optic lobes are exposed, as is usual in the lower orders of birds. 

 The cerebellum is well developed, with strongly projecting 

 flocculi. The medulla presents, in connection with the extreme 

 curvature referred to above, an apparent enlargement of the 

 pons region. This, however, is due to a spreading of the ele- 

 ments rather than to an actual increase in the volume of the 

 medulla. 



Pelicanus erytJiorhyncJios, the white pelican. This brain 

 resembles, as would be expected, the goose brain in its general 

 features. This specimen, taken from a bird with an expanse 

 of wing of 2.5 meters, has a total length of 49 mm., a total 

 breadth of 41 mm. The mass of the prosencephalon, as shown 



by I L. B. D., is less than that of any of the birds given in Profes- 

 sor Turner's tables except the ArdeidiB and the CticididcB, being 

 64.4, as compared to 69.3 for the domestic duck. This is in 

 harmony with the inferior position given to the Pelicanid(B in the 

 systematic works. 



The olfactory lobes were unfortunately mutilated, but seem 

 to have been small, though quite distinct from each other. 

 The dorsal fisure of the cerebrum is very deep in front, but un- 

 like that of the goose brain it disappears entirely behind. Its 

 cephalic end is considerably farther cephalad than in the goose. 

 The optic lobes are much smaller than usual and are almost entirely 

 covered by the cerebrum. The cerebellum, too, is smaller than 

 usual. As is well known, this bird is a very clumsy flier. In 

 order to discover whether the size of the cerebellum is corre- 

 lated with powers of flight, a few comparative measurements 

 have been taken. The comparative volumes of the cerebellum 

 were obtained by the same method used by Professor Turner 

 for the cerebrum. The ratios of the length, breadth and depth 

 of the cerebellum to the total length of the brain, expressed in 

 hundredths, were multiplied and the cube root of the product 

 taken. This gives approximately the ratio of the cube root of 

 the volume of the cerebellum to the total length of the brain. 



