xxviii Journal of Comparative Neurology. 



and medio*caudad and then divide into numerous branches as de- 

 scribed by Kolliker. 



2. The small multipolar cells of the ventral nidulus are recog- 

 nized. The nervous processes are always short and, as Held says, 

 divide frequently. 



3. Adjacent to the above he finds the large nerve cells described 

 by Kolliker, but many of them have the appearance of an ordinary 

 multipolar nerve cell. From a rather far ventral large cell a meso- 

 ventral process could be followed into the corpus trapezoides. Final- 

 ly fusiform cells were found with dendrites at either end. In two of 

 these the nervous process at its proximal end exhibited a very large 

 polar dendrite and such cells as these may have led Sala to the 

 assumption of bipolar ganglion cells with T-shaped fibres. In the case 

 observed there is no doubt that a nervous process arises from a den- 

 drite. In the tuberculum acusticum are similar fusiform cells lying 

 mostly in a transverse position, yet it was impossible in most cases to 

 trace the processes far in the tuberculum acusticum, while in those of 

 the ventral nidulus they all tend toward the corpus trapezoides. 



4. A large part of the fibres entering the tuberculum acusticum 

 first pass through the ventral nidulus and give off collaterals to it. 



5. Cochlear fibres are also found which pass mesad of the tuber- 

 culum acusticum and end far dorsad in terminal brushes in the most 

 distant parts of the tuberculum. Held identifies certain other fibres 

 which pass from this point and, arching about the restiforme, pass 

 again ventrad as a part of the root-fibres of the cochlearis, but Mar- 

 tin is not sure that they do not originate from cells of the tuberculum. 



6. Besides the termination of the vestibular nerve in the two dor- 

 sal terminal niduli of Kolliker (dorsal or main vestibular nidulus or 

 Deiter's nidulus) as well as in the region of the caudal root, the whole 

 gray mass between the floor of the ventricle, the caudal trigeminal 

 root and the corpus restiforme may be considered as a terminal region 

 of the vestibular nerve as also a partially distinct portion of ventral 

 nidulus beneath the restiforme. 



Chromatophores of Cephalopods. 1 



The chromatophores of Loligo, for example, consist of a pigment 

 cell with twenty or more long radial fibres. These fibres have been 

 supposed by the older authors to be muscular and their purpose to 



1 SAMASSA, P. Bemerkungen iiber die chromatophoren der Cephalopoden . 

 Verhandl. natur.-hist.-med. Vereins zu Heidelberg, V, 2. 



