502 Scientific Intelligence. 



tohedral symmetry of the crystal, which were obtained in the 

 successive steps of the process. Perhaps the most remarkable 

 point brought out is the resistance to attack at an extremity of 

 each of the three lateral axes, while in the direction of the verti- 

 cal axis the solution went on very rapidly. Thus in the later 

 stages of the process, after seven weeks, the sphere was flattened 

 to about one-half its original diameter vertically, while in the 

 transverse direction it had almost a triangular form. — Trans. 

 Conn. Acad., vol. viii, 1889. 



13. Seventh Annual Report of the Directors of the United 

 States Geological Survey, TV". Powell, 656 pp. roy. 8vo. — After 

 a review of the organization of the Survey, and a statement of 

 the work in progress and partly accomplished, and the reports for 

 the year 1886 of the heads of divisions, this report contains the 

 following elaborate papers : The Rock-Scorings of the Great Ice- 

 Invasions, by T. C. Chamberlin ; Obsidian Cliff, Yellowstone 

 National Park, by J. P. Iddings ; Geology of Martha's Vine- 

 yard, by N. S. Shaler ; Classification of the early Cambrian and 

 pre-Cambrian formations — a brief discussion of principles illus- 

 trated by examples drawn mainly from the Lake Superior Region, 

 by R. D. Irving ; The Structure of the Triassic formation of the 

 Connecticut Valley, by TV". M. Davis; and the Geology of the 

 Head of the Chesapeake Bay, by TV. J. McGee. There is also a 

 valuable paper on Salt-making processes in the United States by 

 T. M. Chatard. Many fine plates and cuts, mostly from photo- 

 graphs and maps, illustrate these papers. Those of the paper by 

 Chamberlin are very beautiful and effective ; so also those of 

 the Obsidian Cliff showing its columnar features, its lithophyses 

 and spherulites ; and those of the other papers have great interest. 

 Portions or abstracts of the papers of Iddings, Irving, Davis 

 and McGee have appeared in this Journal. A general map of 

 glacial stria? in the United States accompanies Mr. Chamberlin's 

 paper. 



14. Journal of Morphology. — The number just issued (No. 3 

 of vol. ii), of the always excellent Journal of Morphology, of Bos- 

 ton, (published by Ginn & Company), contains an elaborate and 

 admirably illustrated paper by C. S. Minot on the uterus and 

 embryo, I, Rabbit, II, Man ; another, of like character, by E. P. 

 Allis, Jr., on the anatomy and development of the lateral line 

 system in Amia Calva ; the two covering 228 pages and illus- 

 trated by many plates and figures in the text ; besides shorter 

 papers on the organization of atoms and molecules by Prof. A. 

 E. Dolbear; some new facts about the Hirudinea bv C. O. 

 Whitman, and Segmental sense-organs of Anthropod? War. 

 Patten. 



15. On the Development of Manicina areolata / by E V. 

 Wilson. — This is another of the profound researches publr ;-. d in 

 the Journal of Morphology, in vol. ii, No. 2. The pap>. 

 thesis for the degree of Doctor of Philosophy, at th- 

 Hopkins University, honored by the University a year since. It 

 is a study of the embryological development of the species of 



