226 J. B. JOHNSTON, 
to form the descending fibres of the basal bundle. He was unable 
to find the cells of the II type which he says had been described by 
BELLONCI. I have indicated in my preliminary communication (98a) 
that VAN GEHUCHTEN was in error in overlooking short neurites, by 
reason possibly of imperfect impregnation in his preparations. 
F. MAYER (97) describes in Ammocoetes a striatum whose cells 
give rise to “centrifugale Fasern, welche in den Hypothalamus, ins 
Nachhirn und weiter abwärts verfolgt werden”, and a “cortex” con- 
taining cells whose dendrites come into contact with the end-branches 
of the fibres from the mitral cells, and whose neurites form the 
tractus cortico-habenularis. I will not attempt to criticize MAYER’S 
results at this time, as I have begun the investigation of the brain 
of the brook lamprey. The preliminary examination of my pre- 
parations does not seem to bear out MAYERS interpretation of fore 
brain structures. (Cf. page 235 below.) 
The fibre tracts in the fore brain have been worked out chiefly 
by Epincer. He describes (88) the basal bundle connecting the 
corpus striatum with the thalamus in Ammocoetes, Teleosts, Se- 
lachians, Amphibians, and Reptiles. In Teleosts and Sealachians the 
basal bundles have a decussation at their entrance to the thalamus, 
and in Selachians, Amphibians, and Reptiles a part of the bundles 
continue to the medulla. In (92) the results of (88) are for the 
most part confirmed, but the bulbar portion of the basal bundle is 
less prominent in the description. In his second paper on the fore 
brain (96a) EDINGER describes the basal bundle in Reptiles as con- 
sisting of a large bundle to the thalamus and a small bundle to 
the base of the mid brain. In the meanwhile VAN GEHUCHTEN (94) 
described ascending fibres from the hypothalamus in the basal bundle 
of the trout. In the 5th edition of the Vorlesungen EDINGER states 
that all the descending fibres of the basal bundles end in nuclei of 
the thalamus and metathalamus, and gives them the name tractus strio- 
thalamici. In his last paper (99) on the ‘tween brain of Reptiles, 
EDiNGER makes the whole of the tractus strio-thalamicus end in the 
hypothalamus. EDINGER & WALLENBERG (’99a) find the descending 
fibres in the bird having the following disposition: those from the 
striatum end in the nucleus spiriformis mesencephali; those from 
the occipital pole end in the formatio reticularis of the mid brain; 
those from the putamen end in the nucleus rotundus; those from 
the nucleus taeniae end in the nucleus entopeduncularis and central 
grey; those from the dorso-lateral part of the hemisphere in the 
—s 
