568 



the GasseriaD, and only appears as a blunt process of the latter as 

 figured by His. 



Lastly in a short report in "Nature" of May 26*'' Onodi is said 

 to have recently stated that the Ciliary ganglion belongs to the sym- 

 pathetic. This is the old view and probably the correct one. It was 

 revived by van Wijhe, and I only refer to this short account of 

 unpublished work because it does not clear the confusion, as it is not 

 stated what is meant by ganglion ciliare. 



In my account of the early development already given if the 

 reader will substitute Mesocephalic for Ciliary and strike out 

 radix longa wherever it occurs, the account will be correct. But for the 

 sake of completeness I now give a full account of 



The deyelopment of the Mesocephalic (xaiiglion. 



This ganglion is the ganglion of the ophthalmicus profundus'). 

 In the early development the ophthalmicus profundus connects it with 

 the brain, and may still be said to be its root, even when the proximal 

 portion of the nerve and the whole of the ganglion are fused with 

 the Trigeminus. As I formerly pointed out the peculiarity of the 

 second apparent segment to which the ganglion belongs, is the absence 

 (apparently) of a gill-cleft, and certainly the absence of gill muscles. 

 All the branches of the posterior root are absent except one, the 

 suprabranchial nerve or ophthalmicus profundus. This, like all supra- 

 branchial nerves, is concerned with the innervation of the branchial 

 sense organs developed in connection with that segment. From the 

 neural crest of the mid brain of the developing embryo, just before 

 the closure of the neural folds, cells grow outwards and downwards 

 towards a thickened patch of epiblast just above and behind the eye 

 (Fig. 1) and between the first and second somites. Fig. 2. This 

 outgrowth has been seen by Marshall and van Wijhe. Marshall 

 recognised in it the first rudiment of the Motoroculi, and van Wijhe 

 (rightly) that of the ophthalmicus profundus (Fig. 1. O.V.). 



Neither of the observers saw the skin fusion which follows, or 

 the development of the ganglion. 



When the outgrowth reaches the thickened patch of epiblast it 

 fuses with it. (Fig. 1. S.O.) 



Cells are there proliferated off from the skin to form the ganglion 

 (Fig. 2. M.G) and the outer portion of the thickening begins to form 

 the primitive branchial sense organ (Fig. 2. S.O. Fig. 1. 



1) VAN Wijhe op. cit. Beabd op. cit. 



