634 SYMPATHETIC AND OTHER SYSTEM'S OF NERVES. 



Connections of the Spinal Nerves with the Vertebral Ganglia, so far as these 

 supply the Skin, except tliat of the Head and of the Ano-genital Region. 



In this table a number enclosed in brackets indicates that the connection 

 of the spinal nerve with this ganglion has been determined by vasomotor fibres 

 to the limb, or by secretory fibres to the foot. We have already seen 

 (cf. 628) that the fifth and sixth lumbar sympathetic ganglia do not when 

 the plexus is anterior send off pilo-motor fibres ; nor do the seventh and 

 eighth cervical, but these ganglia are merged in the compound ganglion 

 stellatum. 



As we have said, the connections of the several spinal nerves have 

 been chiefly determined for pilo-motor fibres; we may make a brief 

 statement with regard to the other kinds of nerve fibres. 



1. The connection of the vasomotor fibres with the dorsal cutaneous 

 branches of the intercostal and lumbar arteries, has not, in the experi- 

 ments I have made, presented any constant difference from that of the 

 pilo-motor nerves, though sometimes the connection was a little more 

 extensive. 



2. The secretory and vasomotor fibres for the hind-foot of the cat 

 arise from the twelfth thoracic to the third lumbar inclusive. The 

 ganglia which give off secretory fibres are the sixth and seventh lumbar, 

 and the first and second sacral. With one or more of these ganglia, then, 

 the twelfth to the third lumbar nerves must be connected. The exact 

 connections have not been determined, but it appears probable that the 

 twelfth thoracic sends a few fibres secretory and vasomotor to the 

 seventh lumbar ganglia, and that the thirteenth thoracic sends a few 

 such fibres to the first sacral ganglion ; and this connection has, in con- 

 sequence, been inserted in the table. The nerve having the maximum 

 effect on secretion is the first or second lumbar. 



The eleventh thoracic nerve occasionally sends a few secretory fibres to the 

 foot, so that in these cases the eleventh thoracic must send fibres either to 

 the fifth or sixth lumbar ganglion ; this is not represented in the table. 



3. The secretory and vasomotor fibres for the fore-foot arise from 

 the spinal cord by the fourth to the ninth thoracic nerves inclusive, and 



