188 



SCIENCE. 



[N. S. Vol. XX. No. 501. 



This treatise is, in substance, a reproduc- 

 tion in considerably extended form of a series 

 of lectures delivered by the author at the 

 Colloquium held in connection with the sum- 

 mer meeting of the American Mathematical 

 Society at Ithaca, N. Y., in August, 1901. 

 It gives a detailed account of the typical and 

 most important class of problems in the cal- 

 culus of variations — in which an integral de- 

 pending upon a plane curve and containing 

 no higher but the first derivatives of the 

 unknown functions is to be maximized or 

 minimized — with special emphasis upon the 

 progress of the theory during the last twenty- 

 five years. The following topics are treated : 

 (1) The older theory of the first and second 

 variation from Euler to Jacobi, and the crit- 

 ical revision of its foundations and demonstra- 

 tions by DuBois-Eeymond, Scheeffer, Weier- 

 strass and others. (2) Weierstrass's theory: 

 the problem in parameter-representation, the 

 fourth necessary condition; sufficient condi- 

 tions. (3) Simplifications and extensions of 

 Weierstrass's theory (especially by Kneser and 

 Hilbert. (4) The so-called isoperimetric 

 problems. (5) Hilbert's existence tjieorems. 

 The Study of Stellar Evolution: A Popular 



Account of Modern Methods of Astrophys- 



ical Research. By George Ellery Hale. 



The purpose of this book is to tell how the 

 origin, development, and decay of celestial 

 bodies are studied in a modern observatory. 

 The remarkable advances in astronomy during 

 the second half of the nineteenth century, in- 

 cluding the development of great telescopes, 

 the introduction of the spectroscope, the many 

 discoveries made with its aid and the results 

 obtained through the use of photography, have 

 given the study of stellar evolution a prom- 

 inent place in the work of many observatories. 

 The explanations of instruments, and methods 

 are accompanied by illustrations, and the most 

 recent astronomical photographs obtained with 

 the telescopes of the Yerkes Observatory are 

 reproduced in a series of plates. 

 Glacial Studies in Greenland. By Thojias 



ChrOWDER CHAjrBERLIN. 



This book will consist of a detailed descrip- 

 tion of about fifteen Greenland ice tongues, 

 and of a portion of the main ice caj), dwelling 



especially upon the significant features, fol- 

 lowed by a chapter on generalizations, a chap- 

 ter on experiments, a chapter on theoretical 

 deductions and a chapter on the applicability 

 of the generalizations and deductions to the 

 great ice invasions of the past. 



Studies in General Physiology. In two Parts. 



By Jacques Loeb. 



This work will contain some of the author's 

 principal papers on the subjects of animal 

 tropisms, heteromorphosis and artificial trans- 

 formation of organs, artificial parthenogenesis, 

 physiological effects of ions, the efliects of 

 lack of oxygen, function of cell nucleus, etc. 

 These papers have appeared in scattered Ger- 

 man periodicals or as separate publications in 

 German, and many of them are now out of 

 print or inaccessible. 



DR. J. C. McCONNELL. 



In the death of Dr. J. C. McConnell, anat- 

 omist of the Army Medical Museum, which 

 occurred on July 25 at Liberty, N. Y., where 

 he had gone for recuperation, more than one 

 science has lost an efficient coadjutor. Apart 

 from the profession of medicine and anatomy 

 and their application to the duties of his 

 office. Dr. McConnell utilized his leisure as a 

 delineator of objects of natural history, espe- 

 cially shells and fossils, crania and bones. 

 He had for nearly thirty-five years carried on 

 this work, and it is certain that as a draughts- 

 man in black and white line, for scientific 

 purposes, he had no equal in this country, if 

 in the' world. 



About his last important work was the com- 

 pletion of the drawings for the illustration of 

 the still unpublished Miocene volume of the 

 Maryland Geological Survey. Many thousand 

 exquisite drawings had been prepared by him 

 for the National Museum and various surveys, 

 as well as the Army Medical Museum, in the 

 course of his career. To those requiring such 

 service his loss is nothing short of a calamity. 

 In his personal relations Dr. McConnell was 

 attractive and genial. His official associates 

 as well as those who knew him chiefly as an 

 artist, will sympathetically join in the regrets 

 of his bereaved family. 



