May 8, 1903.] 



SCIENCE. 



(39 



For the work itself we have only praise. It 

 is an important contribution to comparative 

 physiology. Egbert Teekes. 



Hakvabd Univebsitt. 



A Course in Invertebrate Zoology. A Guide 

 to the Dissection and Comparative Study 

 of Invertebrate Animals. By Henry Shee- 

 ring Pratt, Professor of Biology at Haver- 

 ford College and Instructor in Comparative 

 Anatomy at the Marine Biological Labora- 

 tory of the Brooklyn Institute of Arts and 

 Sciences at Cold Spring Harbor, L. I. 

 Boston, Ginn & Co. 1902. 

 Dr. Pratt's ' Invertebrate Zoology ' is strictly 

 a laboratory book, intended to give the stu- 

 dent all the information and directions which 

 are needed for the intelligent laboratory study 

 of animals, and nothing more. In this the 

 author has as a rule succeeded admirably. 

 His attempt is to give such practical direc- 

 tions that the student can go on with his 

 work profitably without having an instructor 

 at his elbow. In carrying out this attempt 

 he has not hesitated to give directly such in- 

 formation as is necessary to enable the student 

 to do the work intelligently, and has not at- 

 tempted to disguise his information under the 

 form of questions — a ruse which has proved 

 so disfiguring to many of the recent labora- 

 tory manuals. The absence of pedagogical 

 fads is in fact noticeable and refreshing. 

 The information given is chosen judiciously 

 to accomplish the purpose for which it is in- 

 tended. There are no figures in the book, as 

 the laboratory work takes largely the form 

 of drawing the careful dissections made, and 

 the author has doubtless experienced the 

 strong tendency of students to imitate the 

 figures of the text. Oommendably explicit 

 directions are given for making these draw- 

 ings. 



The plan adopted is to study each one of 

 the larger groups of invertebrates as a whole, 

 several of its representatives being dissected 

 in such a way as to bring out relationships. 

 The first group taken up is the Arthropoda, 

 including study of a wasp, a beetle, a grass- 

 hopper, a caterpillar, a centiped, the crayfish 

 or lobster, a crab, a sow-bug, an amphipod, 



Caprella, larval decapods, a copepod, Daphnia, 

 and a nauplius larva. Somewhat less exten- 

 sive studies are undertaken of the Annelida, 

 the flatworms, Bryozoa, Mollusca, Tunicata, 

 Echinodermata, Cnidaria, sponges and Pro- 

 tozoa. While the directions are comparative, 

 the author has tried to make those for each 

 organism complete, so that every teacher may 

 take up the forms in such order as he chooses. 

 Doubtless most teachers would desire to 

 modify the directions in some points to suit 

 their own methods of work; a lack of pre- 

 cision to be noticed in some cases in the 

 directions for the dissection of some of the 

 more difficult systems of organs may thus be 

 remedied. The main body of the book is fol- 

 lowed by an outline of animal classification 

 and a glossary of the terms used in the direc- 

 tions. 



The book will certainly be found very use- 

 ful both to teachers of invertebrate zoology 

 and to those attempting without the aid of a 

 teacher to obtain some practical knowledge 

 of the anatomy of invertebrates. While the 

 well prepared teacher can usually work best 

 with laboratory directions which he has him- 

 self prepared, even this class will find the 

 book suggestive and helpful. 



H. S. Jennings. 



Ann Aeboe, Mich., 

 April 16, 1903. 



SOCIETIES AND ACADEMIES. 

 GEOLOGICAL SOCIETY OP WASHINGTON. 



At the 141st meeting of the society, held 

 in the assembly hall of the Cosmos Club, 

 Wednesday evening, March 25, 1903, three 

 interesting papers were presented. 



Under the title ' Statics of a Tidal Glacier,' 

 Mr. G. K. Gilbert said in part: 



" An iceberg floats in sea water with about 

 seven eighths of its mass submerged. A gla- 

 cier entering an arm of the sea with a depth 

 less than seven eighths the thickness of the 

 ice continues to rest on the bottom. In the 

 discussion of the origin of fiords it is gener- 

 ally assumed that such a glacier is partly 

 sustained by the sea water, and that the rock 

 bed is to the same extent relieved of ice pres- 



