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SCIENCE 



New Series. TTottva-w TVTa-u- 7 1 SQ7 Single Copies, 15 cts. 



VOL. V. No. 123. rKlJJAY, iViAJC (, 10£7 i . Annual Subsckiption, S5.0Q. 



New Works on Embryology. 



Human Embryology. 



By CHARLES SEDGWICK MINOT, 



Professor of Histology and Human Embryology, Harvard Medical University, Boston, 

 Author of ' 'A Bibliography of Vertebrate Embryology,' ' etc. 



Eoyal 8to, 825 pages, 463 Illustrations, extra muslin, price $6.00 net. 



This work has been accepted throughout the world as the standard authority on Embryology. The subject is 

 comprehensiTely presented. Both those aspects of Embryology important to physicians and those interesting to 

 morphologists have been clearly and thoroughly treated. Much of the work is based on unpublished investiga- 

 tions. Most of the illustrations are new. 



" We do not know a more learned treatise on any subject whatever." Brown-Sequard. 



"It makes a new era in the history of American biological text-books. It is by far the best text-book of the 

 Wnd." c. O.Whitman. 



' ' Written with all the care necessary to render it a classic." Revue Scientifique. 



"A treasure house of embryological literature." W. His. 



"A rich store of facts and of numerous suggestive explanations." A. Milnes Marshall. 



" Each chapter deserves special mention and praise." Montreal Medical Journal. 



"We wish to emphasize the extent to which the author has based his criticisms on his own thorough investi- 

 tigations." je. Bonnet. 



"One feature of especial value is the richness of citations of the work of other students." 



American Naturalist. 



The Development of the Frog's Egg. 



An Introduction to Experimental Embryology. 

 By THOMAS HUNT MORGAN, Ph.D., 



Professor of Biology at Bryn Mawr College, Pa. 



Cloth. 8vo. Price, $1.60 net. 



The object of the book is to give an account of the early development of the egg of the frog in connection with 

 the experimental work that has been done on the egg and embryo. In the first chapter the results of recent experi- 

 ments on the origin of the ovarian egg and of the spermatozoon are described. The chapters that follow are on 

 the fertilization and segmentation of the egg, the formation of the germ-layers, and the experiments in crossing dif- 

 ferent species. 



An account is given of Pfliiger's work on the relation between the planes of cleavage and the direction of the 

 force of gravity, of Koux's experiments on injuring one of the first two blastomeres, of the results of compressing 

 the segmenting egg, and of the general problems involved in the experiments. 



Finally the development of the organs of the embryo and the efi'ects of heat and light on development are de" 



THE MACMILLAN COMPANY, 66 Fifth Ayenue, New York City. 



