34 MESSRS. NEWELL ARBER AND J. PARKIN ON 
show that such simple flowers as those possessed by the Magnoliace are in 
reality compound structures, і. е., very compressed inflorescences. Every- 
thing points in the other direction, namely that the sporophylls (stamens and 
carpels) are borne directly on the main axis of the floral shoot. 
Hallier *, quite recently, has suggested a possible connection between the 
Gnetacez and the Loranthacee. Though agreeing in the main with his 
phylogenetie views respecting the Flowering Plants as a whole, we are 
inclined to regard this as a somewhat rash, though ingenious speculation ; 
especially because it necessitates, as he admits, the nucellus of Gnetum being 
regarded, not as a single ovule, but as a placenta bearing several ovules. 
Finally, then, we may conclude that the study of the Gnetacez does not, and 
does not seem likely to, help us in understanding the phylogeny of existing 
Angiosperms. It would appear more probable that a knowledge of the descent 
of the latter, obtained from other sources, will itself shed light on the 
relationships of the former. 
From a discussion on the vascular structure of seedlings, at the last meeting 
of the British Association at York f, the inference may be drawn that some 
help will be forthcoming from this line of study towards solving the problem 
of the origin of the Angiosperms. So far, the examination of the “ transition ” 
phenomena in seedlings has led Mr. Tansley and Miss Thomas to regard the 
simple type met with in the Dicotyledons, and most of the Coniferze, as derived 
by reduction from the more complicated one found in the Cycads and the 
Araucariez. 
Thus, by way of summary, it may be said that no definite theory, as 
regards the origin of the Angiosperms, has up to the present. been elaborated. 
The views put forward from time to time have been more of the nature of 
casual suggestions. The problem has not yet been separately treated as a 
whole, in all its bearings. The morphologist has perhaps hitherto inclined 
only to a comparison between living members of the race, with neglect of the 
fossil evidence. Тһе paleeobotanist, in approaching the subject, does not 
appear to have arrived at any clear conception of what may be considered the 
primitive features of living Angiosperms. 
In concluding this section of the paper, it is interesting to note that this 
unsolved problem has its parallel in the Animal Kingdom. The origin of the 
highest group, the Mammalia, still remains largely problematical. 
PRINCIPLES OF EVOLUTION. 
Before discussing what we regard as the primitive forms of the various 
organs of the Angiospermez, we would emphasize briefly certain principles 
connected with evolution to which we attach considerable importance when 
attempting to trace the phylogeny of living or extinct races. 
* Hallier (1905). 1 Anonymous (1906) p. 182. 
