CONTENTS. 



III. T. H. Morgan, Ph.D. pages 



The Origin of the Test-Cells of Ascidians . . 195-204 



IV. Edmund B. Wilson. 



The Origin of the Mesoblast-Bands in Annelids, 205-2 19 



V. Howard A vers. 



Concerning Vertebrate Cephalogenesis . . . 221-245 



No. 3. — January, 1891. 



T. S. Watase. 



Studies on Cephalopods. i. Cleavage of the 



Ovum 247-302 



II. J. Playfair McMurrich. 



Contributions on the Morphology of the Actin- 

 ozoa. 2. On the Development of the Hex- 

 actinicB 303-330 



III. G. Baur. 



On Intercalation of VertebrcB 331-33^ 



IV. William M. Wheeler. 



Neuroblasts ifi the Arthropod Embryo . . . 337-344 



V. G. Baur. 



The Pelvis of the Testudinata ; with Notes on 

 the Evolution of the Pelvis in General . . 345-3^0 



VI. C. O. Whitman. 



Spermatophores as a Means of Hypodermic 



Impregnation 361-406 



VII. C. O. Whitman. 



Description of ClQ^sme. V\diW2i 407-418 



Typography by J. S. Gushing & Co., Boston, U.S.A. 



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



