ERT ERU YT 
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THUJA OCCIDENTALIS. 23 
been emitted. The rim of the exostome is particularly at 
this period shining. 
No change appears to occur in the pollen while applied to 
the exostomium, nor does there appear to be in any instance 
an emission of boyaux. The exostome is frequently blocked 
up by pollen, in which no alteration has taken place. The 
nucleus in sphaceolated towards its apex and at the base of the 
membranous prolongation. "The excavation in the apex of 
the nuclens seems to be cleaner, so to speak, sometime after 
the application of the pollen. 
The boyaux are emitted as 1 suspected first from the 
firmness with which the grains of pollen adhere to the parie- 
tes of the excavation, which is absolutely crammed with 
granules of pollen. The boyaux are only generated towards 
the base of this canal. 
There is nothing developed at this period, within the vitel- 
lus the parietes of which are a perfect membrane. This sac is 
filled with a fluid and grumous matter, in which last occur at 
considerable distances, distinct sacculi or cells. The grumous 
matter and the contained cells cohere and appear like a mem- 
@ rane. 
The thece polliniferous are composed of tough membrane, 
apparently not cellular, marked with frequent lines obtuse 
occasionally clavate striz, which are of a light brown colour, 
within this membrane there appears to exista much finer 
membrane. "There are no traces of the fibrous cells so fre- 
quent in the ordinary form of anther, 
Eight days after fertilizatian. 
The excavation of the nucleus is crowded with pollen gra- 
nules, the great majority of which are with the exception of 
some tumefaction, unchanged. The parietes of the lower 
part of the cavity are stigmatic, that is the tissue is papillose 
and lax. The ovula are considerably enlarged, as is likewise 
the cavity of the nucleus. The vitellus is much more cellular. 
The majority of granules have not generated boyaux. 
These appear to penetrate the lax papillose tissue with 
