VOLUME LXVI NUMBER 3 
rik 
DOTANICAL GAZETTE 
SEPTEMBER 1918 
SUSPENSOR AND EARLY EMBRYO OF PINUS 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 242 
JoHN THEODORE BUCHHOLZ 
(WITH PLATES VI-X AND THREE FIGURES) 
It has long been recognized that the embryos of plants furnish 
trustworthy morphological features for comparison in the study of 
phylogeny, but the surprising variations found in the proembryos 
of various gymnosperms have always been more or less of a stum- 
bling block. This work was undertaken with the hope that a more 
critical study of the suspensor and early embryo of Pinus and of 
the phenomenon of polyembryony might prove of value in properly 
interpreting the rather flexible program that has been ascribed 
to this genus. Here it is, also, that we find a striking parallel to 
some of the early cleavage phenomena involved in the biology 
of twins in animals, a subject of some current interest to 
zoologists. 
This paper will limit itself largely to such phases of the embry- 
ogeny of Pinus as were most effectively studied by means of a 
special technique for dissection, developed by the writer, and to a 
discussion of the relation of the early Pinus embryo to other conifer 
types. Certain phases of the later embryo will also be described, 
but the development of the internal features of the late embryo will 
be treated in another paper. 
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