CONTENTS. 



PAGES 



III. Edwin O. Jordan. 



The Spermatophores of Diemyctylus . . . 263-270 



IV. E. A. Andrews. 



Compound Eyes of Annelids 271-299 



No. 3. — December, 1891. 



I. W. B. Scott. 



On the Osteology of Mesohippus and Lep- 

 tomeryx, with observations on the modes 

 and factors of evolution in the Mam- 

 malia 301-406 



II. T. H. Morgan. 



The Growth and Metamorphosis of Tor- 

 naria 407-458 



III. F. Mall. 



A Human Embryo twenty-six days old . . 459-480 



IV. Carl H. Eigenmann. 



On the Precocious Segregation of the Sex- 

 Cells in Micrometms Aggregatus, Gib- 

 bons 481-493 



V. Cornelia M. Clapp. 



Some Points in the Development of the 



Toad-Fish (Batrachus Tau) 494-502 



VI. Charles Hill. 



Development of the Epiphysis in Corego- 



nus Albus 503-510 



VII. Henry V Wilson. 



Notes on the Development of some Sponges . 51 1-5 19 



Typography by J. S. Cushing & Co., Boston, U.SA. 

 Presswork by Ginn & Co., Boston, U.S.A. 



