84 ALBERT KUNTZ 



surface of the maxillary nerve to a point peripheral to the anterior 

 border of the orbit. A considerable portion of the ganglionic 

 mass, as shown in figure 9, lies above the dorsal level of the 

 nerve- trunk. 



The cells which accompany the fibers of the maxillary nerve 

 during the early stages of development, as well as the first cells 

 which become aggregated to form the anlage of the sphenopala- 

 tine ganglion, are identical in appearance with the cells which 

 remain in the semilunar ganglion. As development advances, 

 however, the cells which remain in the semilunar ganghon in- 

 crease in size more rapidly than the cells which have advanced 

 peripherally. The cells composing the anlage of the spheno- 

 palatine ganglion are, therefore, materially smaller than the cells 

 in the semilunar ganglion. If the former were compared with 

 the latter at this time their nervous character might be doubted. 

 The cells in the sphenopalatine ganghon soon begin to increase 

 in size more rapidly, however, and many of them rapidly become 

 differentiated into neuroblasts. 



In embryos 25 to 27 mm. in length, the proximal part of the 

 ganghonic mass described in the preceding stage as stretching 

 along the median surface of the maxillary nerve has advanced 

 farther peripherally. The entire ganglionic mass is now more 

 closely aggregated and a large portion of it still lies above the 

 dorsal level of the nerve-trunk. This condition is illustrated in 

 figure 10 which is taken from a parasagittal section of an embryo 

 of the pig 27 mm. in length. After this stage, the entire gan- 

 glionic mass becomes more compactly aggregated and its position 

 is shifted ventrally until a portion of the ganglion lies below the 

 ventral level of the nerve-trunk and partly or completely sur- 

 rounds the proximal part of a descending branch which arises at 

 this point. 



According to the above observations, the sphenopalatine gan- 

 glion is derived more or less directly from the semilunar ganglion. 

 It becomes connected, in the course of development, with the 

 geniculate ganglion of the facial nerve by the large superficial 

 petrosal nerve. This connection, however, is not made until the 

 anlage of the sphenopalatine ganghon is well estabhshed. The 



