Book Notice. 341 
From a consideration of such fossil evidence as the above, 
combined with a comparison of existing forms of flowers, as 
well as evidence from other sources, which must be passed 
over at present, Messrs. Newell Arber and Parkin* have 
formulated a set of conclusions, which they present as a 
‘Working Hypothesis’ for future guidance. They maintain 
that the simple apetalous types of modern angiosperms are not 
primitive forms, but have been derived by reduction from 
hermaphrodite forms with a perianth; that the unknown ancestor 
of the angiosperms was built, generally speaking, on the plan 
of the Mesozoic Bennetiztes; that the angiosperms are a 
monophyletic group, the monocotyledons having been derived 
from the dicotyledons ; and that entomophily was a primitive 
feature of the race. 
It will be seen from the above outline of new evidence that 
no light has yet been shed on the dark period of the emergence 
of the typical foliage of the angiosperm, and it is in connection 
with this that the practical suggestion of this paper may be 
made. The estuarine beds of Yorkshire have unfortunately 
not yet provided us with any evidence of a microscopic 
character bearing on these problems ; but it is, of course, well 
known that they are extremely rich in well-preserved impres- 
sions of leaf form, and to a less extent of flower form. Might 
not the Research Committees of the Yorkshire Naturalists’ Union 
take this into consideration as a probably fruitful field on which 
to expend some of their energies? The exposures of fossiliferous 
beds along the coast have been well investigated, but there 
would seem to be many promising sections lying further 
inland which have been neglected, and which would repay 
investigation. Systematic collecting from these, with especial 
care expended on localising the exact horizon of all specimens, 
might possibly do something towards elucidating a sequence 
from the cycadean or filicinean type of leaf to the angiospermic 
—hereby contributing in some degree towards the solution of 
one of the greatest botanical problems of the day. 
SS 
We have received the August number of the Nature Reader Monthly 
—a small magazine printed in large type—apparently for the use of school 
children. It deals with a variety of subjects—Poppies, Butterflies and 
Moths, Protective Colouration, the Sea Shore, Rocks and Scenery, etc. 
The language used is generally clear. The pamphlet is edited by Mr. 
F. H. Shoosmith, is illustrated, contains 32 pp., and is sold at one penny by 
Charles and Dibble, London. 
* Journal of Linn. Soc. London, xxxviii. (1907). 
1907 October 1. 
