374 



SCIENCE 



[Vol. V., No. 118. 



individual of all those contained in the plate. 

 It would be interesting to know what effect 

 on the composite its absence would produce. 

 This element of what we may perhaps call 

 prepotency is most likely to disturb these com- 

 posite delineations ; for, though in itself a very 

 interesting phenomenon, it seems to be some- 

 what of an obstacle in this use of the new art. 

 With this great contribution of Galton well in 

 hand, we may at length hope that we shall be 

 able to enter upon the study of that unex- 

 plored realm of the human face, and physiog- 

 noury become a tolerably exact science. Some 

 such process as this seems to offer the only 

 chance of obtaining valuable generalizations 

 in this field of inquiry. 



The citizens' committee of Montreal, formed 

 to arrange for the entertainment of the British 

 association last summer, has every reason to 

 be congratulated on the success of its enter- 

 prise. Not only was the meeting a marked 

 success in every point in which the citizens' 

 committee had power to contribute to it, but 

 the report presented at its final meeting a fort- 

 night ago showed with what care it had em- 

 ployed the funds intrusted to it. Parliament 

 granted $20,000 toward passage-money to the 

 British members ; and this was so carefully ex- 

 pended and accounted for, that there remains a 

 considerable sum (about $2,600) to cover in 

 to the treasuiy, — a new experience for a par- 

 liamentary grant of this sort. The Dominion 

 government further voted $5,000 for general ex- 

 penses, the corporation of Montreal an equal 

 sum, and the citizens subscribed $4,580.97. 

 This, too, has been managed with such care, 

 that, apart from the expenses of the meeting, 

 the committee is able to publish an edition of 

 fifteen hundred copies, largely for gratuitous 

 circulation, of a volume of economic papers, 

 and then have on hand a surplus of $1,500. 

 This the committee recommended should be 

 given to McGill college in recognition of, and 

 partial compensation for, its liberality in pla- 

 cing the building and grounds of the university 

 at the disposal of the association. This was 



voted with the understanding that it should be 

 used in some special way, such as for prizes 

 or scholarships, to commemorate the meeting 

 of the British association in Montreal. The 

 success of the work of the committee was be- 

 lieved to be largely due to the excellent judg- 

 ment and unwearied service of Mr. D. A. P. 

 Watt and Lieut. -Col. Crawford, to the former 

 of whom his associates presented a pleasing 

 memento. 



LETTERS TO THE EDITOR. 



*** Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



The ontogeny and phylogeny of the hypo- 

 glossal nerve. 



It cannot be otherwise than gratifying when two 

 investigators, travelling along entirely distinct paths, 

 unknown to each other, find themselves suddenly 

 brought face to face upon the same stand-point. 

 Haeckel's dictum, that the ontogeny of any form is a 

 brief recapitulation Of its phylogeny, is continually 

 receiving confirmation, and, taking into considera- 

 tion cenogenetic modifications, may be accepted as 

 a dogma. If, then, a theory as to the past history 

 of any form or organ which has been deduced from 

 embryological data is also to be deduced (and that, too, 

 independently) from comparative anatomical studies 

 of adult forms, there are strong reasons for its ac- 

 ceptance. 



A case of this kind has occurred quite recently. 

 Since van Wijhe's interesting and important obser- 

 vations on the mesoderm segments of the elasmo- 

 branchs, the view that the hypoglossal nerve has 

 been derived by a separation of fibres from the ven- 

 tral roots of the vagus has very generally been ac- 

 cepted. In a paper very shortly to appear in the 

 ' Studies from the biological laboratory of the Johns 

 Hopkins university,' an entirely different view will 

 be supported. 



From a comparative study of the origin and dis- 

 tribution of the anterior cervical nerves in the 

 various orders of the class Pisces, I have been led 

 to the conclusion that the post-occipital nerves, as 

 they may be termed, of Amia and other ganoid 

 forms, are comparable to the anterior cervical nerves 

 of the elasmobranchs, and in the teleosts and mar- 

 sipobranchs have passed backwards, and become in- 

 corporated with the first spinal nerve. The apparent 

 first spinal, therefore, represents three nerves. In the 

 urodelous Amphibia, one finds, however, an arrange- 

 ment more similar to what obtains in the elasmo- 

 branchs, there being in the anterior spinal region 

 three distinct nerves, whose combined distribution 

 resembles very closely that of the first spinal nerve 

 of the teleosts, and may therefore be considered its 

 equivalent. In the Anura there is a reduction in the 

 number, the first nerve disappearing, or fusing with 

 the second, so that two nerves here fulfil the function 

 of the original three. in all these ichthyopsidan 

 forms there is no true hypoglossal, this nerve making 

 its appearance in the Sauropsida. From its distribu- 

 tion, it is apparently homologous with the three an- 

 terior spinal nerves of the urodelous Amphibia. As 



