482 Bashford Dean 'Memorial Volume 



its fibers both from the lateral line lobe and the acusticum. Whether these latter fibers are 

 all strictly laterosensory ones, as Norris and Hughes conclude, or are in part to be compared 

 to the communis fibers that enter into the trigeminus in the Teleostomi, seems to me still an 

 open question. The three fine nerve strands said by Merritt Hawkes to be sent from the 

 Gasserian ganglion to the facialis ganglion are evidently general sensory ones, as Merritt 

 Hawkes suggests. 



In one respect, according to Hawkes (1906), the facial nerve is in an unusually 

 priraitive condition, in that it has a remnant of the post'trematic ramus quite separate 

 from the truncus hyomandibularis. Hawkes states that a chorda tympani, as defined by 

 Cole (1896) and by Herrick (1899), is present; but Allis (1923) writes that the so-called 

 chorda tympani described by Hawkes seems to be a ramus pretrematicus internus and 

 hence, according to recent opinion, not the chorda. Further, the ramus mandibularis 

 internus passes internal to the ligamentum mandibulo-hyoideum and then forward along 

 the internal surface of the mandible, supplying the tissues of that region. This nerve, 

 according to Allis, is a ramus post'trematicus internus facialis and is the one now generally 

 considered to represent the chorda tympani. 



Hawkes describes, in Chlamydoselachus, a small branch of the glossopharyngeal 

 nerve innervating neuromasts. A branch similar in function has been described in 

 Squalus acanthias by Norris and Hughes (1920), but they state that in Raja radiata 

 there are no lateral line elements in the ninth nerve. 



Brohmer (1909) finds, between the facialis acusticus and the glossopharyngeal 

 nerves of his 25'mm. embryo, a small ventral root (Text-figure 118, Gl.v.) which he inter- 

 prets as belonging to the glossopharyngeal. He thinks it likely that this ventral root 

 disappears in later stages, and names it ''the rudimentary ventral root of the glosso- 

 pharyngeal nerve." Goodrich (1918.2) represents (by a dotted Hne in front of gl.) this 

 root in his schematic Text-fig. 1, reproduced as Text-figure 117 herein. 



Garman (1885.2) states that in his specimen ''The tenth pair (vagus) is somewhat 

 asymmetrical, having eight roots on one side and twelve on the other. There are also 

 four pairs of ventral roots near the median line." Hawkes (1906) states that the vagus 

 arises by from nine to twelve roots from the hinder end of the medulla. The lateralis 

 root, which is the most cephalad, is invariably large, the remainder are small. These 

 small roots are not symmetrical in number and arrangement even in the same fish, much 

 less do they agree in different fishes. The roots arise at the same level, being arranged in 

 an arc which extends along the side of the medulla to the beginning of the spinal cord. 

 The roots cannot be assigned to the separate rami, and the ganglia of the vagus cannot 

 be separated completely by gross methods. The ramus lateralis vagi unites closely with 

 the true vagus in the ganglionic region. There is a sixth ramus branchiaHs vagi which 

 passes toward the remnants of the seventh branchial arch. Hawkes found no trace of 

 any median ventral roots uniting with the vagal complex. Commenting on Carman's 

 statement concerning the presence of ventral roots in his specimen, Hawkes writes: 

 "If Garman were right, his specimen suggests the retention of the somatic motor compo- 



