SCIENTIFIC LITERATURE. 



851 



sive description of the experience ; and on 

 term should be used without the psychical 

 manifestation described by it being pointed 

 out. After an introduction in which the 

 method and place of psychology, subjective 

 and objective, physiological and genetic, are 

 referred to, the elementary facts of con- 

 sciousness are discussed. The coherency of 

 knowledge is treated of in the next chap- 

 ter, and in the third, Psychical Analysis and 

 the conception of unobserved consciousness ; 

 and the succeeding chapters are devoted to 

 Sensation, Memory, and Fancy; The Objec- 

 tive World, Truth and Error, and Feeling 

 and Will. (Published at Leipsic, Germany: 

 B. G. Teubner.) 



An extremely interesting book is given 

 us in the publications of the Wisconsin Geo- 

 logical and Natural History Society of studies 

 by George W. and Elizabeth Peckham, of the 

 Instincts and Habits of the Solitary Wasps. 

 These insects are familiar enough to us all, 

 as we meet them or see their nests of one or 

 a few cells every day, and then think no 

 more of them. But Mr. and Mrs. Peckham, 

 following them to their haunts and keeping 

 company with them, have found them mani- 

 festing remarkable instincts and exercising 

 curious customs, which they describe in the 

 style of persons who are in love with their 

 work. The opportunity for the studies was 

 given in two gardens, one on the top of a hill 

 and the other lower down, with an island in 

 a lake close by and acres of woodland all 

 about, offering a rich variety of nesting places. 

 There are more than a thousand species of 

 these solitary wasps in the United States, to 

 only about fifty of the social ones, and they 

 live without knowledge of their progenitors 

 and without relations with others of their 

 kind. 



The eighth volume of the report of the 

 Iowa Geological Survey comprises the ac- 

 counts of surveys completed during 1897 in 

 six counties, making up the whole number 

 of twenty-six counties in which the areal 

 work has been completed. This does not, 

 however, represent the whole extent of the 

 operations of the survey, for some work has 

 been done in nearly every county in the 

 State, and in many counties it will require 

 but little additional work to make a complete 

 report. In addition to the areal work, too, 



special studies of coal, clay, artesian waters, 

 gypsum, lead, zinc, etc., have engaged atten- 

 tion. A growing public appreciation of the 

 work of the survey as illustrated in the de- 

 mand for the volumes of the reports and for 

 special papers, is recognized by the State 

 Geologist, Mr. Samuel Calvin ; and an in- 

 creasing use of the reports as works for 1 ef- 

 erence and for general study in high schools 

 and other educational institutions is observed. 

 The survey is now collecting statistics of pro- 

 duction of various minerals mined in the 

 State. 



One of the features most likely to attract 

 attention in the Annual Report of the State 

 Geologist of New Jersey for 1897 is the 

 paper of Mr. C. C. Vermeule on the Drain- 

 age of the Hackensack and Newark Tide 

 Marshes. In it a scheme is unfolded for 

 the reclamation and diking of the flats, un- 

 der which an ample navigable waterway 

 shall be developed, and the cities which now 

 stop at their edges may be extended and 

 built up to the very banks of the new har- 

 bor, made a highway for ocean sailing ves- 

 sels. An interesting paper is published by 

 Lewis Woolman on Artesian and Bored and 

 other Wells, in which many important wells 

 are described with reference to the geologi- 

 cal strata they penetrate. Other papers re- 

 late to iron mining and brick and clay indus- 

 tries, mineral statistics, and statistics of 

 clays, bricks, and terra cotta. The field re- 

 ports describe progress in the surveys of the 

 surface geology, the Newark system, and the 

 upper Cretaceous formations. 



On the basis of a reconnoissance made by 

 him for Alexander Agassiz, Mr. Robert T. 

 Hill has published through the Bulletin of 

 the Museum of Comparative Zoology at Har- 

 vard University, a paper on The Geological 

 History of the Isthmus of Panama and Por- 

 tions of Costa Rica. He finds that there is 

 considerable evidence that a land barrier in 

 the tropical region separated the two oceans 

 as far back as Jurassic time, and continued 

 through the Cretaceous period. The geo- 

 logical structure of the Isthmus and Central 

 American regions, so far as investigated, 

 when considered aside from the paleontology, 

 presents no evidence by which the former ex- 

 istence of a free communication of oceanic 

 waters across the present tropical barriers 



