peesident's addeess. 33 



less affected the course of development and disguised the real 

 relationships. It was argued, that the development of no one 

 type afforded an absolute guide to principles; only when the 

 whole of the facts become known could adequate generalisations 

 be arrived at. Professors Huxley and Parker had some years 

 ago been led to view the trabeculse cranii, the primary elements 

 underlying the base of the fore part of the brain, as non-axial, 

 but as comparable to the visceral arches or mandibular hyoidean 

 and branchial series. Some of their main reasons appeared 

 to be that the trabeculse in several types arose distinct from 

 the axial parts at the hinder part of the skull, that in the 

 early flexure of the fore part of the brain, about the end of the 

 notochord or dorsal axis, the trabeculae became correspondingly 

 down-bent so as to be more or less parallel with the visceral 

 arches, and that a very constant distribution of a branch of the 

 great trigeminal nerve seemed to be analogous to the distribution 

 of nerves in the facial arches. But many considerations now 

 induced Professor Parker and Mr. Bettany to abandon that view, 

 and rather to regard the trabeculae as proper axial elements. 

 Some of these were, that the trabeculae arise in tissue imme- 

 diately underlying the cerebral cavity just as the vertebrae arise 

 in tissue beneath the spinal canal, that the temporary meso- 

 cephalic flexure does not make the tissue other than axial, while 

 the proper axial position is early resumed, that every relation of 

 the trabeculae proper is to the nervous centres, and that cartila- 

 ginous growths continuous with them bound the cranium later- 

 ally, just like the formation of the lateral occipital or vertebral 

 regions. Further, it was sought to show, that reckoning the 

 trabeculae as axial elements, they probably possessed their own 

 appendicular parts in the pre-nasal and ante-orbital region. It 

 was contended, that in the face of these facts it was in the 

 highest degree undesirable to consider the fore part of the skull 

 as a mere modification of facial appendicular parts, and that 

 there were strong reasons for a recurrence to the earlier, more 

 natural, and simpler conception, that the most important part 

 of the skeleton had its own proper axis, and did not borrow it 

 from without. 



