216 J. B. JOHNSTON, 
The longitudinal tract which has been best known is the tractus 
strio-thalamicus of EDINGER. I leave the detailed examination of 
this until I come to the fore brain. The tract contains both ascending 
and descending fibres. The ascending fibres go from the corpus 
mammillare to the epistriatum of the same and opposite side; the 
descending fibres come from the olfactory nuclei and from the 
striatum. The only other tract entering the lobus inferior is the 
tractus tecto-lobaris. I have discussed this above (page 127). 
The bundles arising in the lobus inferior have been very imper- 
fectly described. EDINGER in the 5th edition of the Vorlesungen 
mentions a tractus lobo-cerebellaris frontalis et caudalis, in two 
bundles coming respectively from the cephalic and caudal portions 
of the lateral wall of the lobus inferior and running to the cerebellum. 
These bundles correspond to a part of my tractus lobo-cerebellaris 
et bulbaris (page 125). EpInGER has not seen the crossed portion 
which decussates behind the chiasma, and has overlooked the fact 
that a part of the bundle continues into the medulla. He does, 
however, describe a tractus thalamo-bulbaris et spinalis (p. 67 and 
127). It seems probable that this and the tractus lobo-cerebellaris 
are parts of a single system equivalent to the tractus lobo-cerebellaris 
et bulbaris which I have traced out with great completeness and 
entire certainty in Acipenser. The radiatio thalami which EDINGER 
describes in his last paper on the ‘tween brain (99) is probably the 
bulbar portion of the same system in Reptiles. Its origin by two 
bundles, one medial and one lateral (near the geniculatum), and the 
fact that they run somewhat dorsally and turn ventrally at the level 
of the commissura posterior, indicates a close similarity to this tract 
in Acipenser. 
Our knowledge of the tuber cinereum of man is too incomplete 
to admit of detailed comparison with the lobus inferior of fishes. 
There is correspondence of position, and the longitudinal bundle 
through the tuber to the corpus mammillare may correspond to the 
ascending fibres of the tractus strio-thalamicus of lower Vertebrates, 
or to descending fibres from the olfactory nuclei (KOLLIKER). 
The physiology of the lobus inferior of fishes is relatively simple. 
It receives tracts from the olfactory and optic centers and sends 
tracts to the motor centers of the medulla (and cord?), and to the 
cerebellum to set up secondary connections with the motor centers. 
The corpus mammillare probably receives a share of the fibres 
from the olfactory centers in fishes, and in all animals above fishes 
