j?OLLEN-BODIES OF THE ANGIOSPERxMS. 
35 
as a group from the larger cell only by a wall of cortical 
plasm. In some isolated cases this may become a resisting 
(cellulose ?) membrane. 
The Pollen-tube is formed from the large cell. It may 
happen that the vegetative cell or cells have nothing to do 
with this occurrence, so that the nucleus and contents of the 
large cell alone immigrate into the tube. The separating wall 
is generally, however, absorbed. It may vanish altogether 
after the division; in most cases it however remains for a 
certain time ; the whole vegetative cell or cells loosen them- 
selves from the inner wall of the Pollen-body, and are then 
surrounded by the large cell, which appears strangely 
spindle- or half-moon shaped. The vegetative cell may 
remain in this state a longer or shorter time, or its nu- 
cleus may divide, and thus free-swimming vegetative cells 
be formed. In either case the "wall of plasm is finally 
dissolved ; this may take place either in the Pollen-body or 
after the vegetative cell has gone into the tube. A division 
of the naked vegetative nucleus may take place after the 
disappearance of the wall, and this may also occur either 
in the Pollen-body itself or in the tube. 
The nuclei have often strange forms. I have noticed no 
division of the nuclei of the large cell, except in the 
Cyperaceae. 
A particular order is not generally kept in the migration 
into the tube. The nuclei are dissolved sooner or later ; but 
in any case before fertilisation takes place. The large cell 
of the Pollembody and its nucleus appear to be of more im- 
portance for fertilisation than the vegetative one. I arrive 
at this conclusion from the following facts, viz. that it is 
the large cell which grows into a Pollen-tube ; from the 
circumstance that in some cases the nucleus of the large cell 
always goes in front, while I never saw the opposite case as 
a constant characteristic; that in those plants where this is 
not the case, the nucleus of the large cell still goes oftener 
ill front than the other; finally, that in some instances the 
vegetative cell remains in its original position without 
entering the tube at all. 
