The Morphology of Cosmobia 419 



appear fairly well-developed median rudiments of several nerves beyond 

 the Sixth, probably representing not only all of the remaining cranial 

 nerves, but a few of the most anterior spinal nerves as well. Thus, a 

 little posterior to the Sixth nerve a long ganglionic ridge extends longi- 

 tudinally in the mid-ventral line. At least two pairs of nerve roots 

 run into it from the sides of the medulla and it is attached also at its 

 posterior terminus, presumably by a pair of roots that arise so close 

 together as to form a median mass. Posterior to this and still in the 

 median line are two farther nerves which may be regarded as cranial, 

 the first smaller and the second larger. These arise as median roots and 

 run as single fibers in a straight course, keeping in the median plane. 

 About opposite these ventrally lies a large median ganglion, entirely 

 detached from them and from the cord, yet from this proceed two pairs 

 of nerves, the anterior ones very fine and short, the posterior ones larger 

 and longer. These nerves seem soon to lose themselves in the surround- 

 ing tissues. 



The interpretation of the above structures, although not capable of 

 exact proof, is suggested by beginning at the Gasserian ganglion, the 

 last point of certainty, and following the roots posteriorly [cf. Fig. 29]. 

 In this way it seems as though the long median mass composed of several 

 pairs of roots may be the Facialis-Acusticus complex, and the two 

 median roots posterior to this the Glosso-pharyngeus and Vagus. The 

 detached ganglion is less certain, at least until after a careful determina- 

 tion of the rudimentary structures to which its nerves are distributed, 

 but it is probably either the ganglion petrosum of the Ninth or the gan- 

 glion nodosum of the Tenth, or possibly both together. 



For some distance beyond these median cranial nerves a median row of 

 nerve roots is continued, so that for each body segment the cord has 

 three roots, the two normal ones upon the sides and a mid-ventral one, 

 the latter composed of two elements. Posteriorly these latter grow 

 constantly smaller and narrower and the former come nearer together 

 until the median row is wholly lost and the relations become normal. 



Case 2. (Teras XII.) This specimen, also a pig, gives a suggestion 

 of what the monster just described would have looked like, had it been 

 allowed to develop to maturity, since it also is a single individual with 

 a double snout [Fig. 30] . Here, however, the divergence and separation 

 of the two components is not quite so great, and the two inner eyes, 

 instead of being separate, form a single median organ of abnormal width, 

 though containing two separate lenses. This amalgamation, or rather 



