THE MALE GAMETOPHYTE OF ABIES 
A. H. HutcHinson 
(WITH FIFTEEN FIGURES) 
In a study of Abies balsamea as a type of the Coniferae, a num- 
ber of irregularities in the contents of the pollen grain have been 
observed. Since the material used was collected from different 
trees and in different years, these irregularities cannot be regarded 
as abnormalities; and since further examination showed that 
similar conditions prevail in at least two other species of Abies, 
these observations have been thought worthy of record. 
For the material I am indebted to Professor R. WILSON SMITH. 
A. balsamea was collected in Ontario; A. Veitchii and A. brachy- 
phylia were obtained through the courtesy of the authorities of the 
Royal Gardens at Kew. 
The pollen grain of Abies balsamea is very large, its diameter 
being about twice that of Pinus. At the time of shedding the 
normal grain contains two prothallial cells, a stalk cell, a body 
cell, and a tube nucleus, imbedded in a vacuolated protoplasmic 
mass which contains numerous starch grains (fig. 1). ‘The nucleus 
of the body cell is surrounded by dense protoplasm and a ce 
membrane. The tube nucleus is large and usually compressed; 
some instances the pressure, resulting from the extraordinary 
growth of the cells of the gametophyte, is insufficient to force it 
from its polar position to a lateral one. The stalk cell is much 
smaller than the body cell, and quite frequently is compressed into 
a cavity at the prothallial end of the latter. In A. Veitchit and 
A. brachyphylla the prothallial cells are very much flattened at 
this stage; but in A. balsamea it is not uncommon to find both 
prothallial cells retaining the characteristic nuclear structure. 
The size and permanence, however, varies with the individual as 
well as with the species. 
The material examined does not show stages earlier than the 
division of the central cell into generative cell and tube nucleus. 
Peculiarities in this division are described later. The periclinal 
Botanical Gazette, vol. 57] [148 
