Preface 



CONTEMPORARY botanical science is characterised by great activity 

 along many different lines. From time to time, therefore, it becomes 

 necessary, certainly desirable, to bring together the observations and 

 conclusions relating to major topics. Embryogenesis in Plants is such a 

 theme. The embryology of species from different taxonomic groups has 

 long provided subjects for research by the traditional methods of the 

 anatomist and histologist, the results in the main being regarded as a 

 contribution to comparative morphology. There is still scope for further 

 work along these lines. During recent years, however, new ideas and 

 experimental techniques have been applied to the investigation of 

 embryos, and new evidence, some of it of a fascinating interest, and 

 suggestive of great possibilities for further work, is beginning to accrue. 

 This statement applies not only to the seed plants but to other groups 

 also. In the present comprehensive survey — the first of its kind — the 

 author has described, illustrated, and discussed the embryological 

 development in all classes of plants, from Algae to Angiospermae, 

 references to the dynamic aspect and to experimental work being 

 incorporated wherever possible. An attempt has been made to offer some 

 explanation of the visible embryological developments in terms of the 

 genetical, physical, and other factors and relationships which may be 

 involved, and to show how such an approach promotes an under- 

 standing of the parallelisms of development, or homologies of organisa- 

 tion, found in all the major taxonomic groups. The traditional theme 

 of the bearing of the evidence from embryology on evolutionary and 

 phyletic theory is also fully considered. It is hoped that the book thus 

 contains matter of interest to all botanists, teachers and research 

 workers alike. 



Borrowed illustrations are duly acknowledged and here the author 

 would like to express his thanks to all concerned. Sincere thanks are 

 offered to Professor P. Maheshwari and Messrs McGraw-Hill, New 

 York, for the use of illustrations from An Introduction to the Embryology 

 of Angiosperms, to Professor D. A. Johansen and Messrs Chronica 

 Botanica Co., Waltham, Mass., for the use of illustrations from Plant 

 Embryology, to Messrs Macmillan & Co. for the use of illustrations 

 from books by the late Professor F. O. Bower and Professor D. H. 

 Campbell, to Professor R. Soueges and Professor A. Lebegue for the 

 use of illustrations from their Memoirs, and to the Editors and Publishers 

 of the following journals for the use of illustrations : Annals of Botany; 



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