» Ml 
Structure and Development of the Ovule of Bowenia 
spectabilis . 1 
BY 
E. M. KERSHAW, M.Sc. 
Assistant Lecturer in Botany , Manchester University. 
With Plate LXI and sixteen Figures in the Text. 
‘HIS investigation was undertaken in the hope that it might increase 
J. our knowledge of Cycads, and also give further information on points 
of interest in connexion with the study of fossil seeds, more especially with 
regard to the development and fate of the pollen-chamber. No detailed 
account of the ovule of Boivenia has yet been published, and it seems 
desirable that every genus of such a limited and ancient family as the 
Cycads should be investigated. 
The greater part of the material was obtained some years ago by 
Professor Lang from the plants of Bowenia growing in the Royal Botanic 
Gardens, Kew. All this material was unpollinated, but it supplied an 
almost complete series of stages from an ovule with only the megaspore 
cell developed to one almost ready for pollination. The rest of the Kew 
material consisted of aborting ovules of two sizes, the smaller about the size of 
a wheat grain, the larger the size of a small hazel nut. Although these were 
abnormal they afforded much useful information. This material was sup- 
plemented by a batch of old pollinated ovules (Fig. 9, PI. LXI, actual size), 
collected from the Botanic Gardens, Tokyo, by Dr. M. C. Stopes, to whom 
I am indebted for the material. While the series is thus an incomplete one, 
a good general idea of the changes in form and structure of the ovule can 
be obtained from it. Much of the development shows close agreement with 
that described by various authors 2 for other genera, but the chief stages 
will be briefly described, since they help to fill in some of the gaps in the 
various accounts. They also contribute to the data necessary for a com- 
parative review of our knowledge of the ovule of Cycads, which it is hoped 
1 A preliminary account of this investigation was read before Section K of the British Association, 
Portsmouth, 1911. 
2 Warming: Oversigter d. K. dan. Vidensk. Selsk. Forhandl., 1877 and 1879. Treub : Ann. 
Jard. Bot. Buitenzorg, vol. ii, 1882 ; vol. iv, 1884. Lang : Ann. of Bot., vol. xiv, June, 1900. 
[Annals of Botany, Vol. XXVI. No. CIII. July, 1912.] 
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