On the Double Nature of the Cycadean Integument. 
BY 
MARIE C. STOPES. 
I NTEREST in the morphology of the ovules of living Cycads has been 
much stimulated by the recent appearance of several papers dealing 
with the structure of Cycad-like seeds of Carboniferous age. The structures 
found in these fossils are not only of great interest in themselves, but also 
seem to throw light on some of the difficult points in the morphology 
of recent seeds, and it became clear that a detailed examination of the 
living forms might be undertaken with advantage. This I attempted 
to do, publishing the chief details with a short outline of the results in 
August, 1904 l . 
In support of my views on the nature of the Cycad integument, 
through the kindness of Prof. Oliver, I was enabled to use certain facts 
discovered by him in the fossil Lagenostoma ; but my paper was written 
prior to the publication of the full monograph on Lagenostoma which 
appeared almost simultaneously with it 2 . A large paper by M. Matte 3 , 
in which one of the sections treats of the Cycad ovule, appeared almost 
at the same time, so that the author had seen neither the full work on 
Lagenostoma nor mine on the Cycads. 
In their monograph on Lagenostoma the authors state (p. 334) : 
‘A comparison of the seeds of Cycads with Lagenostoma is inevitable, 5 and 
further: ‘ In any case, the detailed structure of Cycadean seeds is a subject 
fully deserving of further attention and elucidation. 5 
As it happened that the three papers dealing with the Cycads and 
Lagenostoma appeared simultaneously this comparison has not yet been 
fully made. I will not attempt to do this now in detail, but there are one 
or two points about which I should like to add something to my published 
views. 
Work on the anatomy and morphology of living Cycads revealed that 
their integumentary structure is more complex than was generally 
1 Stopes, Beitiage zur Kenntnis d. P' ortpfianzungsorgane d. Cycadeen. Flora, Bd. 4, 1904. 
2 Oliver and Scott, ‘ On the structure of the palaeozoic seed Lagenostoma Lomaxit Phil. 
Trans. B., vol. cxcvii, 1904. 
3 ‘L’appareil libero-ligneux d. Cycadacees.’ Caen, 1904. 
[Annals of Botany, Vol. XIX. No. LXXVI. October, 1905.] 
Q q 2 
