No 437-] 



NOTES AND LITERATURE. 



(3) Helminthology treated in this way, may also aid paleonto- 

 logical research, since the relations between parasites and hosts, and 

 their migrations and geological age, permit conclusions to be drawn 

 as to the age of the single larger groups (of the parasites) and even 

 of their genera and species. A. E. O. 



Two papers on the Nautilus. 1 — These two works which appeared 

 nearly simultaneously form the most important contributions to our 

 knowledge of the tetrabranch cephalopods which have appeared for 

 years. Dr. Griffin had for his material numerous specimens collected 

 by the Menage expedition of the Minnesota Academy of Sciences, 

 while Dr. Willey collected his among the islands of the Eastern 

 Archipelago where he went in the hopes of obtaining the embryology 

 of this most interesting animal. 



Neither of the papers — which extend over 95 and 91 pages and 

 are illustrated by several text figures and 1 7 and 9 plates respectively — 

 can be summarized here. The two, to a great extent, supplement each 

 other. Dr. Griffin has endeavored to give a connected account of the 

 anatomy, utilizing not only his own dissections but the accounts of 

 his predecessors and hence gives a wealth of detail. Willey on the 

 other hand describes rather what he himself has investigated and his 

 comparisons are those of the broader morphological treatment. A 

 single example will illustrate the different points of view. In treating 

 of the digital tentacles Willey gives comparatively little about the 

 anatomical structure but tries to work out a numerical nomenclature 

 of these parts, in which he comes to results widely at variance with the 

 previous studies of Vayssiere. Griffin, on the other hand describes 

 the anatomy in great detail, but says nothing regarding the arrange- 

 ment, although he knows of Vayssiere's work. He gives however a 

 plan of their position which differs in some respect from that of 

 Willey. Willey further enters with the question whether these tentacles 

 are to be compared to the arms of the dibranch cephalopods or to the 

 acetabula as has been suggested, inclining to the former view. 



The sections relating to the foot in Dr. Willey's paper are of 

 interest. Accepting Grenacher division of the molluscan foot into a 

 median protopodium and lateral epipodia and discussing change of 

 function and its relations to change of organs and to topography he 

 argues for the conclusion that the siphon represents the protopodium 



Science, viii, 1900 (1902). — Willey's Contribution to the Natural History of the 

 Pearly Nautilus, in his Zoological Researches, part vi, August, 1902. 



