OLFACTORY CENTERS IN TELEOSTS 229 
side or ventral to the recessus preopticus (figs. 54, 61). These 
are probably homologous with the ‘Lingsfasern des kleinzelligen 
Kerns’ of Goldstein and are, perhaps, concerned with the move- 
ment of cerebro-spinal fluid. 
Immediately ventral to the recessus preopticus Goldstein fig- 
ures and describes a small tract (Taf. 11, fig. 7), the connections 
of which he was unable to identify. Fig. 62 shows a parasagittal 
section in which the relations of this tract are clearly shown (fr. 
preopt. sup.). It is entirely unmedullated and arises from small 
stellate cells (fig. 63) immediately ventral to the recessus preop- 
ticus, terminating partly in the nucleus parvocellularis posterior 
and partly in the nucleus magnocellularis. 
The most important longitudinal caudal connection of the 
nucleus preopticus is the large unmedullated tractus praethalamo- 
cinereus. This originates largely from the nucleus magnocellu- 
laris as described by C. L. Herrick and Kappers, the fibers extend- 
ing latero-ventrad (figs. 72, 73, 76). A part of the fibers, however, 
originate from cells of the nucleus intermedius and nucleus par- 
vocellularis anterior (figs. 69, 72), while a few arise in the nucleus 
parvocellularis posterior (fig. 76). At first, the tract lies near 
the median line (figs. 69, 72, 73) but it gradually turns ventro- 
laterad (fig. 74) to lie ventral to the lateral forebrain bundle 
(figs. 76, 77, 79). As it is unmedullated and, therefore, of the 
same color as the tractus strio-thalamicus fibers, it is easily mis- 
taken for a part of that tract and was undoubtedly so considered 
by the earlier authors. Immediately caudal to the postoptic 
commissures it bends ventro-mesad, entering the nucleus lateralis 
tuberis (fig. 80), where undoubtedly some of its fibers terminate, 
and where it probably also receives accessions. Goldstein de- 
scribes and figures this tract but apparently considers it a part of 
the tractus strio-thalamicus, as he traces the latter tract, but not 
the former, into the nucleus lateralis tuberis. From this nucleus 
the tract extends ventrad into the nucleus ventralis tuberis (fig. 
80) where it doubtless undergoes the same change as in the nucleus 
lateralis tuberis, thence passing on into the hypophysis, of which 
it forms the chief innervation, to terminate particularly in the 
