Page:Popular Science Monthly Volume 54.djvu/875

Rh 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 consciousness are discussed. The coherency of knowledge is treated of in the next chapter, and in the third, Psychical Analysis and the conception of unobserved consciousness; and the succeeding chapters are devoted to Sensation, Memory, and Fancy; The Objective 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 Geological 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 manifesting 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 accounts 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 attention. A growing public appreciation of the work of the survey as illustrated in the demand for the volumes of the reports and for special papers, is recognized by the State Geologist, Mr. Samuel Calvin; and an increasing use of the reports as works for reference and for general study in high schools and other educational institutions is observed. The survey is now collecting statistics of production 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 Drainage of the Hackensack and Newark Tide Marshes. In it a scheme is unfolded for the reclamation and diking of the flats, under 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 harbor, made a highway for ocean sailing vessels. 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 geological strata they penetrate. Other papers relate to iron mining and brick and clay industries, mineral statistics, and statistics of clays, bricks, and terra cotta. The field reports 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 Zoölogy at Harvard University, a paper on The Geological History of the Isthmus of Panama and Portions 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 geological 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 existence of a free communication of oceanic waters across the present tropical barriers