THE RAMI OF THE FIFTH NERVE IN AMPHIBIA. 
By G. E. CoGuite. 
With Plate V. 
In a study of the components of the cranial nerves of 
Amblystoma I have found very suggestive relations existing 
between the ramus ophthalmicus profundus V and the ramus 
palatinus VII. This observation has led me to review the 
conditions generally described in Amphibia, and to my own 
mind the Amblystoma is extremely helpful in interpreting the 
relations between certain rami of the fifth nerve in Urodela on 
the one hand and the Anura on the other. 
My observations upon Amblystoma tigrinum have been 
made from serial sections of the heads of larvae of different ages 
and of the adult head also. The series were cut transversely 
ten micra thick, and in both planes longitudinally. Those of 
the larva were hardened in FLEmmMING’s stronger solution, di- 
luted in some cases, and stained on the slide after WEIGERT. 
The adult head was stained zz fofo according to vom Ratu. For 
comparison I have made also a series, cut transversely, of the 
head of a larva of Rana ata stage some time previous to the 
appearance of the hind limbs. This series is absolutely con- 
tinuous through the region in question and is satisfactorily 
stained with the WeEIGERT method after fixation of FLEMMING’s 
stronger solution. It has enabled me to supplement STRONG’s 
description of the ‘‘accessory rami’ of the trigeminus and to 
show their relation to certain nerves in Amblystoma. 
In Amblystoma the lateral line ganglion of the seventh 
nerve, associated with the Gasserian ganglion, is microscopically 
distinguishable from the latter. It gives off two rami which 
arise in close contact with one another from the most dorsal 
portion of the common ganglionic mass. In the adult these 
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