126 JOURNAL OF COMPARATIVE NEUROLOGY. 
with confidence on the latter point, because I have now in an 
advanced state of preparation a study of their connections and 
internal organization based on an extensive series of sections by 
several standard histological methods, including the methods of 
WEIGERT and GOLGI. 
It will not be necessary for me at this time to report these 
histological observations further than to say that they abund- 
antly confirm the conclusions to which JonnsTon was led in his 
studies of Acipenser (’01) and Petromyzon (’o2), that the 
primary and secondary connections of the communis system 
within the brain are absolutely distinct throughout from those 
of either the general cutaneous or the acustico-lateralis systems. 
This I regard as a matter of the highest importance to any es- 
timate of the morphological interpretation of the sense organs 
innervated from these various centers 
We may now turn to the consideration of the function of 
the terminal buds. This is a matter to which I have devoted 
considerable attention during the past year and with results 
which I think may be regarded as decisively answering the 
question. A preliminary account of these experiments was 
presented to the American Association for the Advancement of 
Science at the Pittsburg meeting (Abstract appearing in Sczence, 
HERRICK, ’02) and the final report upon the problem is,now in 
press in the Bulletin of the U. S. Fish Commission at Wash- 
ington. From that report I excerpt the following summary of 
results. 
The entire cutaneous surface of Ameiurus is known to be 
supplied with terminal buds, and particularly the barblets. In 
the gadoid fishes terminal buds are known to be present on the 
barblet and on the free filiform rays of the pelvic and dorsal 
fins. Accordingly I chose as the chief subjects of investigation 
Ameiurus nebulosus, the common ‘horned pout,’ Microgadus 
tomcod, the ‘tom cod,’ and Urophycis tenuis, the ‘hake,’ to- 
gether with a number of fishes such as Prionotus and Opsanus 
in which microscopical examination has shown that terminal 
buds are absent from the outer skin (MorriLi, ’95 and 
CLAPP, ’99). 
i Di 
