70 Serentifie Intelligence. 
form, the tubes of which have to penetrate the longer pistil of 
the long-styled form, are larger than the grains from the other 
form.” “This curious relation led Delpino (as it formerly did me) 
to believe that the larger size of the grains is connected with the 
greater supply of matter needed for the development of their 
on ubes.” But it proved that, in many cases where the 
pollens differ mach in size, the styles differ moderately in length 
1 
? 
a ce versa, and that in plants generally, there is no close 
relationship between size of pollen and length of style (the grains 
ing of the same size in Datura arborea and in Buckwheat 
while the style of the one is nine inches long and of the other 
very short); yet still “it is difficult quite to give up the belief 
that the pollen grains from the longer stamens of heterostyled 
plants have become larger in order to allow of the development 
i 
and it would have been of little use to such plants to beco 
heterostyled e can thus understand why it is that not a single 
enera are mentioned which ‘have probably passe 
on from the heterogone condition to the diwcious, Coprosma is 
tendencies in the same direction. On the other han , Mr. Dar- 
8 observations on Ewonymus Europeeus are “ very interesting, 
h : 
obvious tendency towards dicecism, the principal illustrations are 
: : . 
, ete, 
The eighth and last — is devoted to Cleistogamic flowers. 
nds of flowers are evidently arran 
~ 
a n 
howy blossoms, produce others which fertilize and fructify with- 
