422 
CARL S. HOAR 
To be sure there may be indications of reduction in some instances 
with regard to the reproductive structures, but on the other hand, such 
investigators as Nawaschin have found good grounds for supposing 
that there are very important primitive features in connection with 
the formation of the male cell which lead to a very different conclusion. 
That Juglans should show a condition part way between the Gymno- 
sperms and the higher Angiosperms would appear to constitute a 
strong point against the contention that any great reduction has taken 
place. Moreover, the vegetative anatomy of the Casuarinaceae is 
most certainly primitive. Nearly every organ in this family shows 
primitive features although they are sometimes accompanied by char- 
acters common to the higher forms. Granting the close relationship 
to the Casuarinaceae it does not seem possible to regard these amen- 
tiferous forms as belonging anywhere but low in the evolutionary 
scale of the Dicotyledons. There are, also, other points which are, 
perhaps, best mentioned here. The species of all these families are 
characterized by having the egg fertilized from the lower side through 
the chalaza. Such a type of fertilization, as has been stated, is 
commonly known as chalazogamy in contrast to the type found 
throughout all the Monocotyledons and higher Dicotyledons. This 
latter type is called porogamy. In the latter, also, the pollen-tube 
grows down the style of the pistil and instead of following the wall of 
the ovary, as in the case of the chalazogamous forms, grows directly 
through the intervening space and into the egg-sac by way of the 
micropyle. The chalazogamous type is confined, among the Dicotyle- 
dons, to the amentiferotis forms in general and is plainly not of high 
evolutionary character. We find an instance of a similar condition 
among the Gymnosperms in the Araucarineae. Here, in the case of 
the genus Araucaria, the pollen falls upon the ligule. It does not 
grow directly down to the micropyle but follows the tissues of the 
ligule and scale until it attains a position immediately below the ovule. 
Upon arriving at this point, it grows straight upward through the 
lower side of the megasporangium and reaches the egg from the 
bottom. In the chalazogams the pollen falls upon the stigma and 
the pollen tube grows down through the solid tissue into the egg. 
Apparently the situation in those members of the Dicotyledons charac- 
terized by chalazogamy is intermediate between the case in the Gymno- 
sperms and that in the higher Angiosperms. The grains of pollen no 
longer fall upon the ovule but the condition has not yet been reached 
