EARLY ONTOGENETIC PHENOMENA IN MAMMALS. t 
Early Ontogenetic Phenomena in Mammals and 
their Bearing on our Interpretation of the 
Phylogeny of the Vertebrates. 
By 
A. A. W. Hubrecht. 
With 160 ‘lext-figures. 
PREFACE. 
In the present paper I have attempted to bring together 
the results of new investigations and recent reflexions with 
such as had already been published on earlier occasions, but 
which, having appeared in very different periodicals and publi- 
cations (789, 790, 794, 795, 796, 799, 702, ’05, 07), could not be 
easily brought into the necessary connection with each other 
by the reader. 
I have to thank my friend Sir Ray Lankester for giving 
me the occasion to present this scattered material in a more 
concise form, and for his willingness to admit a profuse 
quantity of process figures into a JournaL which, under his 
direction, has become justly famous for its excellent litho- 
graphic plates. 
TABLE OF CONTENTS. 
PAGE 
PREFACE : : ; , i iL 
Cuap. 
I, THe Earutest CEeLi-LAYERs. 
Introductory ; ‘ : : 3 
VOL 53, PART 1.—NEW SERIES. 1 
