SCIENCE. 



Editorial Cojimittee : S. Xewcomb, JIathematics ; K. S. 'Woodwarp, Mechanics ; E. C. Pickering, As- 

 tronomy ; T. C. JIexdexhall, Physics ; R. H. Thubstox, Engineering ; Ira Rejisex, Chemistry ; 

 J. Le Coxte, Geology; W. M. Davis, Physiography; O. C. Marsh, Paleontology; W. K. Brooks, 

 Invertebrate Zoology ; C. Hart Merbiam, Vertebrate Zoology ; S. H. ScfDDER, Entomology ; 

 N. L. Brittox, Botany ; Hexry F. Osborx, General Biology ; H. P. Bowditch, 

 Physiology ; J. S. Billings, Hygiene ; J. McKeex Cattell, Psychology ; 

 Daxiel G. Bbixtox, J. W. Powell, Anthropology. 



Friday, Jtoie 14, 1895. 



CO^f TEXTS: 



The Lowest of the Vertebrates and their Origin : 

 Theo. Gill 645 



Cunint Xotes on Anthropology ( IX. ) .• 



D. G. Brixtox 649 



Current Xotes on Physiography ( IX. ) : 

 W. M. Davis 651 



Science in Canada : J. T. C 653 



Correspondence : — 656 



1'olcanic Dust in Utah and Colorado: Hexry 

 Montgomery. Volcanic Dust in Texas: E. T. 

 Dumble. On the Cla.mtication of Skulls: G. Sergi. 



Scientific Literature : — 658 



(ienlngicnl and Xatural History Surrey of Minne- 

 sota : William B. Clark. Fossil Mammals 

 of the Putrco Beds : W. B. .ScOTT. Ridgiray's 

 Ornithology of Illinois: C. HaET SIebRIAM. 

 Tests of Gloir-Lanips : T. C. 51. 



Xotes and Xetcs : — 663 



Entomology; A Xew Quadruple Expansion En- 

 gine : Papers for the Mathematical Congress at 

 Kazan : The Royal Geographical Society ; The Xa- 

 tional Geographic Society ; Botanical Books at Auc- 

 tion ; General. 



Societies and Academies : — 668 



Geological Society of Washington ; The Xetc York 

 Academy of Science. 



Scientific Journals : — 670 



TJie Physical Jieriew ; TIte Journal of Comparaiire 

 Xeurology. 



MSS. intended for publication and books, etc.. intended 

 for review sbould be sent to the responsible editor, Prof. J. 

 McKeen Cattell, Garrison on Hudson. X. Y. 



Subscriptionsand advertisements stiould be sent to Science, 

 41 X. Queen St., Lancaster. ?a., or 41 East 49th St., New York. 



THE LOWEST OF THE VERTEBRATES AXD 

 THEIR ORIGIX.* 



In many seas have been found — and in 

 almost all temperate and tropical seas may 



* CoUiuibia I'nirersity Biological Scries. II. Amphi- 

 oxus and the Ancestry of the Vertebrates. By Abtuir 

 WiLLEY, B. He, Tutor in Biology, Columbia College. 



be found — small animals of peculiar appear- 

 ance and habits and of extraordinary inter- 

 est. They have a translucent, compressed 

 and elongated fusiform body attenuated at 

 both ends, and therefore have received one 

 of their names — Amj/hioxtts; this form may 

 be superficially modified, however, by the 

 development of a membrane around the 

 caudal portion of the bodj- and the exten- 

 sion downwards of cirri fi-om an oral ring. 

 The existence of these cirri and the erro- 

 neous attribution to them of a respiratory 

 function have given rise to another name 

 for the gi'oup — Branchiostoma. Lancdet is a 

 semi-popular equivalent of Branchiostoma 

 and Amphio.cu.'i. 



The animals thus distinguished externally 

 are unique in their organization. The 

 nervous system is manifest in an elongated 

 tube without any expansion forwards into 

 an externally specialized brain, and with its 

 anterior portion only distinguished by the 

 fact that there are (in front of the first my- 

 otome) two sj-mmetrical pairs of sensory 

 nerves which innervate the snout and have 

 no corresponding ventral roots. A skeleton 

 is represented by a simple notochord ex- 

 tending to both ends of the body, and there 

 is no rudiment of a cerebral case or of sense 

 capsules ; the only other hard parts are de- 

 veloped around the anterior aperture, where 



With a preface by Hexky Faibfield Osbokn. 

 Macmillan <.t Co. 1894. 8vo, xiv+316. Frontis- 

 piece. §2.50. 



