xc Journal of Comparative Neurology. 



other and the septum. " As a result of the slight development of 

 Jacobson's organ Stetson's ducts do not develop. These develop 

 elsewhere through separation of an epithelial duct during the closing 

 of the gum processes and almost uniformly lie about at the place 

 where the primitive choana open into the mouth cavity." As a re- 

 sult of the peculiar formation of the nasal passages it is natural that 

 in crocodiles they should stand in close relations to the rudimentary 

 fundaments of Jacobson's organ. The organ after assuming the form 

 of a considerable sac-like appendage to the passage occupying an ex- 

 cavation in the vomer, it undergoes retrogression. The highest stage 

 of development is readied when the embryo is 91^ mm. long in 

 Crocodilus porosus. The author thinks it, on the whole, improbable 

 that the predecessors of Crocodilia had a completely developed Jacob- 

 son organ. The old idea that Jacobson's organ and Jacobson's cartilage 

 are to be correlated is an error. This cartilage (Luschka's or Jacob- 

 son's) is simply the basal part of the primitively simple cartilaginous 

 nasal capsule. It correspond's apparently to what Gaup called 

 solum nasale in the frog. The Jacobson's organ of man lies high up, 

 far above the b^sales narium cartilage, which has its usual position. 



Infantile Niicleary Degeneration.^ 



In this paper a series of observations are collected bearing on the 

 perplexing problem involved in paralysis ot the eye-muscles of central 

 origin. The first section embraces opthalmoplegia exterior with or 

 without paralysis of the facialis. The second section relates to bilat- 

 eral abducens-facialis paralysis, the third with congenital bilateral ab- 

 ducens paralysis, the fourth with bilateral oculomotor paralysis, the 

 fifth with bilateral ptosis, and the sixth and seventh with unilateral 

 abducens paralysis and ptosis. Curiously enough no cases are known 

 of congenital bilateral facialis paralysis unaccompanied by abducens 

 paralysis. 



The development of the degeneration may be gradual but the 

 result is persistent and beyond amelioration. The differential diagno- 

 sis especially as against tertiary syphilitic and labitic oi^hthalmoplegia 

 is discussed, but the confession is made that nothing is known of the 

 pathological anatomy. 



1 MoBius, P. J. Ueber infantilen Kernschwund. Mi'aichener Med. Ah- 

 handlungcn, VI, 4. 



