468 



Fi(j. 3. The letters have the same signification in all the figures. 



c. c. central cavity; 5 brain ; Inf. infundibulum ; n. c. nerve cells; n. f. nerve fibers; 

 m. e. mouth epithelium; tb tubules of the glandular part; s bony wall of skull; e. p. 

 epithelium of the hypophysis; c. to. cartilaginous wall of the skull. 



In connection with this figure I will mention an interesting feature, 

 which appears to throw some light on the question as to the source 

 of the nerve supply of the glandular part, and at the same time, to 

 emphasize the intimate connection, which has been already mentioned 

 between this and the nervous portion. In sections through this part 

 the nerve cells in the side near the glandular tissue, appear to send 

 prolongations directly downward into this mass — and there to 

 spread out among the tubules — as represented in a slightly dia- 

 grammatic manner in the figure. The connection of the fibers with 

 the nerve-cells was distinctly visible in only one or two cases, as the 

 stain of the specimen was not specially adapted to bring out finer 

 nerve-structures, but the stem of fibers all distinctly originate in the 

 same region, and I think it may be safely assumed that they all 

 originate in ganglion nerve-cells which form a "special nervous center" 

 for the hypophysis-innervation. 



The question as to the special nerve supply of the hypophysis in 

 other forms appears to have attracted but comparatively Httle atten- 

 sion from the various observerse. Edinger says in his work on the 

 Scyllium: "Möglich wäre es aber, daß die Hypophysis ein eigenes aus 

 Ganglienzellen stammendes Nervensystem enthält. Da ich nie irgend 

 etwas Ganglienähnliches in ihr gesehen habe, so ist es doch sehr un- 

 wahrscheinlich." Thus the condition which he mentions as improbable 

 appears to be the fact in the case of the Calamoichthys. The most 

 interesting feature of the hypophysis in this form remains to be 



