Geology and Mineralogy. 457 



authors on pages 205-213 of this volume. Mr. Dale's paper on 

 *' Structural details in the Green Mountain region," is described 

 on page 395. Mr. Harry Fielding Reid contributes an illustrated 

 report on " Glacier Bay and its glaciers," with numerous important 

 statistics regarding the general features and the changes now go- 

 ing on in this Alaskan glacier region. 



In the , paper "Some analogies on the lower Cretaceous of 

 Europe and America," the author, Lester F. Ward, in the first 

 part makes comparison of the Potomac formation with that of 

 the Wealden of England, and finds reason for considering them 

 closely related as indicated by their respective floras ; secondly, 

 the scaly clays of Italy, their cycads and the age of the beds are 

 discussed ; and thirdly, the Jurassic and Cretaceous floras of 

 Portugal are com))ared with the corresponding floras of America. 



3. Biological Lectures, Wood's IIoll, summer season of 1895. 

 pp. 1-188, 1896 — The latest number oi this series contains several 

 papers of general interest. 



Two of the lectures were on the head segments of vertebrates. 

 William A. Lacy in " The primary segmentation of the verte- 

 brate head," reaches the conclusion that there are normally 

 fourteen neural segments. He says: "The human brain is 

 not a homogenous mass of tissues, but a complex compound of an 

 aggregation of about fourteen brains all united into a working 

 whole." Professor G. S. Kingsley, in the following lecture, on 

 "The segmentation of the head," after noting the varying inter- 

 pretations of previous investigators, accepts the observations of 

 Mr. Lacy as to matters of fact, but hesitates to adopt his inter- 

 pretation, remarking that " while we can say that there are cer- 

 tainly more than the three or four segments of Oken and his 

 followers, we cannot say exactly what the number is. Before 

 the answer is placed beyond a doubt, a number of other questions 

 must be solved, not the least of which is the broader problem of 

 the origin of metamerism and the relation of this condition in the 

 vertebrates to that in the lower forms." Significant, as bearing 

 upon this latter sui^gestion, is the recent address of Dr. Gaskell, 

 before the physiological section of the British Association this 

 summer, on the " origin of vertebrates," in which he traces it to 

 the raerostomata, chiefly by means of the neural segmentation. 



Another investigation presented in the Wood's HoU series is 

 on " the transformation of Sporophyllary to vegetative organs," 

 by Professor George F. Atkinsox. The author observes the 

 remarkable facility with which the normally differentiated sterile 

 and fertile leaves of the Onoclea sensibilis replace one another. 

 He drawls the conclusion that the sporophylls are primary organs, 

 here agreeing with Bower, and are transformed into vegetative 

 leaves. Aside from this special result of the investigation, the 

 remarkable variability in the degree of difl"erentiation of the two 

 kinds of leaves is a warning, especially to paleobotanists, against 

 drawing too hasty generalization from the separate fragments of 

 fossil ferns met with in the rocks. 



