11) if 
IV. 
II. 
CONTENTS] OP VOL« XII. 
No. 1. — May, 1806. 
KATHARINE Foor. 
Yolk-Nucleus and Polar Rings 
. WILLIAM PATTEN. 
Variations in the Development of Limulus 
Polyphemus . 
W. E. RITTER. 
Budding in Compound Ascidians, based on 
Studies on Goodsiria and Perophora . 
FRANK E. LILLIE. 
On the Smallest Parts of Stentor capable 
of Regeneration; a Contribution on the 
Limits of Divistbility of Living Matter. 
Tuos. H. MontTGomery, Jr. 
Organic Variation as a Criterion of De- 
velopment 
No. 2. — February, 1897. 
C. O. WHITMAN AND A. C. EYCLESHYMER. 
The Egg of Amita and its Cleavage . 
Tuos. H. MONTGOMERY, JR. 
On the Modes of Development of the Meso- 
derm and Mesenchym, with Reference to 
the Supposed mag of the Body 
Cavities . 
17-148 
149-238 
239-249 
251-308 
309-354 
355-306 
