4 BOTANICAL GAZETTE [JULY 
sporophyll are being rapidly corroded. The persistence of this 
starch in the mother-cells during division and its disappearance 
as the exine is formed in the pollen grain agrees with what is 
already known in cycads and conifers. The ripe pollen 
grain contains no starch, nor is any found in the pollen tube 
until it appears in the protoplasm of the central cell shortly 
before the formation of the sperm cells. The number of micro- 
sporangia ona sporophyll may be as many as nine, seven being 
a common number. The wall of the mature microsporangium 
consists of but two layers of cells on the exposed surface, and in 
this respect Taxodium differs from the Abieteae, Taxeae, 
Cycadales, and Ginkgo, and agrees with the e Cupresseae and 
Gnetales. The cells of the outer layer of the wall have the 
sides and inner faces strengthened by bands of cellulose, while 
those of the inner layer are very much flattened and poor in 
contents. The cells in the tapetum have very dense contents 
and are shorter and thicker than those of the inner wall. They 
disorganize at about the time that the division occurs in the 
pollen grains. 
The division of the pollen mother-cells took place this year 
(1901) in South Carolina on March 6th, and both divisions were 
found on the same day, even in the same cone, but the stages 
found in the same sporangium are not quite so different as 
Coulter and Chamberlain (’or) figure for Pinus Laricio. Changes 
of the nucleus leading up to the first division were not 
present in my material, but good preparations of all stages during 
and subsequent to the metaphase of the first division show that 
the phenomena are similar in all essential respects to those 
described in detail by Strasburger (’00) for Larix. 
The chromosomes, as arranged on the nuclear plate, are 
short and thick (fig. 3). They stand at right angles to the axis 
of the spindle, the fibers being attached to the inner ends. The 
splitting begins at the point of attachment and in favorable 
cases the line may be seen between the two halves in the as yet 
unseparated outer limb. Very soon after the splitting is com- 
pleted and the daughter chromosomes begin to move to the 
poles, the fibers are seen to be attached to the middle of the 
