372 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



Five nerves (the tenth, eleventh, twelfth, thirteenth and four- 

 teenth) enter into the supply of the musculature of the ventral fin, 

 branches for the superficial muscles forming an independent plexus 

 from that into which the branches for the deep muscle enter. 



A general scheme for the more posterior nerves is represented in 

 Fig. 6, PL IV., in which the rami dor sales are seen to furnish branches 

 for the R. lateralis V. as well as branches for the interspinous muscles. 

 Each R. ventralis, as described by Stannius, crosses over an inter- 

 muscular septum into the following myotome, where the branches 

 (Rmv) for the ventral parts of the lateral musculature are given off, 

 and then all are connected by two longitudinal cords (like nervi col- 

 lectors) from the nodal points of which the branches for the deep 

 (Rmp) and for the superficial musculature (Rnis) of the anal and 

 caudal fins are derived. The infracarinal muscles are supplied by 

 nerves which are apparently homodynamous with those going to the 

 superficial musculature of the fins. 



The nineteenth to the thirty-third rami, ventrales take part in the 

 innervation of the anal fin, while the caudal fin receives the succeed- 

 ing nerves, of which the two last pairs consist only of very strong 

 ventral branches corresponding to the terminal swelling of the up- 

 turned tip of the spinal cord. 



SYMPATHETIC NERVOUS SYSTEM. 



I have not devoted any attention to the sympathetic system ; a 

 thorough study of it, especially in its relations to the somewhat 

 puzzling suprarenal capsules of the Teleosts, would no doubt yield 

 facts of much interest. 



The most readily-detected ganglia are to be found on the sides of 

 the body of the first vertebra, giving off there branches with the 

 branches of the aorta, as well as the ganglionated cord backwards 

 along each of those vessels. Two branches of large size pass for- 

 wards and downwards under the branchial veins and are joined by a 

 transverse commissure under che basioccipital. Thence the anterior 

 communicating branches to the ganglia of the vagus and trigeminus 

 gi-oups pass forwards. 



III. ORGANS OF SPECIAL SENSE. 

 Although my detailed observations have been confined to what is 

 unquestionably the point of highest interest in connection with the 

 sense organs — the relationship of the air-bladder to the auditory 



