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on the lateral surface of the head is removed, these muscles adhere 

 to it, thereby exposing the nerve. 



After administering chloroform to the mole, the skin and super- 

 ficial muscles on the side of the head were laid back. The temporal 

 nerve, the branch to the protuberance, and the remaining portion of 

 the temporal nerve, which is distributed to the buccinator muscle, 

 Avere dissected out for several millimeters and stimulated electrically. 

 At different intervals each nerve was given a number of single in- 

 duced shocks by an inductorium (modification of Rumkoff Coil) with 

 platinum electrodes. The results were as follows: 



1. Temporal branch (Fig. 5, TN). — When this nerve was stimulated 

 electrically, there was invariably a vigorous contraction of the buc- 

 cinator muscle, showing a strong motor response. 



2. Nerve (Z) to the protuberance. — To this nerve numerous 

 single induced shocks were applied, but in no instance was there a 

 response. 



3. Nerve (X) continuation of the temporal. — The electrical 

 stimulations of this nerve were followed by repeated contractions of 

 the buccinator muscle, indicating a motor response. 



From this experiment the following inferences were drawn: 



(a) The temporal branch of the auriculotemporal division of the 

 mandibular nerve is both sensory and motor in function. 



(b) The ramus supplying the protuberance is purely sensory. 



(c) That part (Z) of the temporal nerve, which is distributed 

 to the buccinator muscle, contains motor fibers. 



The presence in the cheek of the mole, of a well developed 

 protuberance containing large vibriassae and supplied by a strong sen- 

 sory nerve, naturally brings up the question of its function. In the 

 laboratory, the moles were kept in boxes containing six to eight inches 

 of moist dirt. From time to time, when the animals were out of 

 their burrows, the vibrissae were touched, and, invariably, a move- 

 ment of the snout toward the stimulus resulted. Usually, at the same 

 time, the corresponding fore foot was raised, producing what appeared 

 to be an attitude of defence. Little acquaintance with these animals 

 either in captivity or in nature is necessary to convince one that 

 they are extremely susceptible to vibrations of the earth about their 

 burrows. The position of this organ upon the head, and the length 

 of its vibrissae, are such that in digging a new burrow and, usually, 

 in traversing an old one, the distal ends of the vibrissae are brought 



