sol JOURNAL OF COMPARATIVE NEUROLOGY. 
ing questions to the solution of which Dr. EpinGer has applied him- 
self during several years. The very satisfactory results published in this 
paper EDINGER attributes in large part to the codperation of WALLEN- 
BERG and Hotmgs, which made it possible to study a very wide range 
of material, representing all the chief types of birds, and to study the 
course of fiber tracts by the degeneration method... The attempt 
to describe the centers and fiber tracts in so complete a manner that 
they may be recognized in any group of birds, may be regarded as 
fairly successful. 
The key to the interpretation of the bird fore-brain is found in its 
development. ‘The fore-brain in the early embryo presents the typical 
arrangement: a thick ventral wall formed by the basal ganglion and an 
extensive pallium forming the roof of the wide ventricle. The basal 
ganglion, however, grows much more rapidly than the pallium and 
eventually obliterates a large part of the ventricle and fuses with the 
pallium over the greater part of the lateral and dorsal regions. The 
ventricle becomes reduced to a narrow medio-dorsal cleft connecting 
occipital and frontal horns, the latter extending into the olfactory lobe. 
The parts of the pallium thus fused with the basal ganglion have been 
overlooked or wrongly interpreted by previous authors. It is usually 
marked off from the basal ganglion by a layer of cells or by a layer of 
medullated fibers—the Stabkranz—and even where it is not so marked 
its structure and connections, as weil as its developmental history, show 
that it is a true pallium. 
In the basal ganglion the author has identified the epistriatum and 
the nucleus thaeniae and their fiber tracts, the relations being essentially 
the same as in the brain of reptiles. The remainder of the basal gan- 
glion, which is very greatly enlarged as compared with that of any 
other vertebrate, consists of a ventro-median mesostriatum, a dorsal 
hyperstriatum, and a lateral ectostriatum. ‘The ventro-anterior end of 
the mesostriatum is divided into two nuclei, a median lobus_parolfac- 
torius and a lateral nucleus basalis. Although there are great differ- 
ences in the size and functional importance of these two nuclei and of 
other parts of the basal ganglion, the brains of all birds agree in the 
main features. ‘The fibers from the pallium and the hyperstriatum 
form a medullated fiber layer, the lamina medullaris dorsalis, over the 
dorsal surface of the mesostriatum which corresponds to the capsula 
interna of mammals. The fibers then pass downward through the 
mesostriatum to form the brachia cerebri on its ventro-caudal surface. 
A true capsula interna is occasionally present (parrot). | It is as yet 
