48 MESSRS, NEWELL ARBER AND J. PARKIN ON 
ancestors, and all inferior ovaries from ancestors in which these organs were 
superior. 
The ovule in the primitive Angiosperms was orthotropous. This view is 
also that commonly held”. From this primitive type were derived the 
campylotropous and anatropous types. 
We are inclined to regard the primitive carpel as multi-ovulate f. There 
is, however, a constant tendency to reduction in the number of ovules among 
monocarpellary ovaries. This is especially well seen in an order such as 
Ranunculacese. The significance is to be found in the fruits, which commonly 
become indehiscent and one-seeded, 7. e., achenes. 
The Microsporophylls and Microsporangia. 
The type of mierosporophyll and mierosporangium, found almost throughout 
the living Angiosperms, is a very constant one on the whole, and this indicates 
that these are organs which have become fixed, although in many cases there is a 
strong tendency in the direction of abortion, suppression, or transformation. 
We regard the stamen as а sporophyll, equivalent to the modified foliar organ, 
which сап be shown to have existed in the case of the Pteridospermez 
or Paleozoic ancestor. This sporophyll bears two synangia, each, in. some 
respects, similar to the male organ of a Pteridosperm, e. g., Crossotheca. 
The synangial view of the stamen is by no means a new one, but hitherto 
no attempt has been made to link it with an ancestor, also possessing 
this type of mierosporangium. We shall endeavour to show at a later stage 
(pp. 67, 68) that such a view is tenable. 
Among living Angiosperms, we regard the andreecium as primitive in such 
an order as the Magnoliacez, especially as regards the spiral arrangement, 
the indefinite number, and the form of the microsporophylls and mierospor- 
angia. The shortness of the filament, the length of the connective, and its 
continuation beyond the anther as a sterile tip, are important features in this 
connection. We are thus in general agreement with Hallier { as regards 
the microsporophylls of Angiosperms. From such a type of stamen, later 
stages in evolution have involved modifications of the connective and 
filament, resulting in the basifixed and versatile types of anther. 
The Perianth. 
Tt has been already shown that Angiospermous flowers without a perianth, 
or those in which this organ is insignificant, occur in plants possessing dense 
inflorescences. Solitary naked flowers, with many stamens and carpels, are 
almost unknown to us. In consequence of these two facts, we believe that 
* Coulter & Chamberlain (1904) р. 57. t Prantl (1888). t Hallier (1903). 
