88 Morphology BOOK I 



Bower's views, saw the primitive flower initiated some- 

 where among the strobili of the Pteridophyta, such as those 

 of Equisetum or the Lycopodinae, traced it through the 

 cones of the Gymnosperms, and found it appearing in the 

 Angiosperms already complex and showing a high degree 

 of differentiation, provided with a perianth of at least one 

 series of members and with modified sporophylls, and though 

 showing its strobiloid character by the spiral arrangement 

 of its members, approximating to what the adherents of the 

 other school held to be a highly specialized type. On such 

 a hypothesis as this the so-called primitive flowers of 

 Engler were held to be due to reduction. Bower himself 

 suggested in 1894 the comparison of the flower of the 

 Phanerogams with the strobilus of Pteridophyta, but he 

 refrained from definitely claiming them as homologous ; 

 indeed, he pointed out a difficulty in accepting such a posi- 

 tion, in that the homosporous strobili are entirely non- 

 sexual, while this is not the case with the flowers of Angio- 

 sperms. At the same time it will be remembered that the 

 strobili of Selaginella contain both micro- and mega-spor- 

 angia. Bower was quite emphatic in opposing the old view ; 

 he said, ' in any case there seems no sufficient reason to think 

 that . . . the Phanerogamic flower ever was a foliage shoot.' 

 Though there seems reason from Bower's work to look 

 for the primitive flowers among the strobiloid structures of 

 the Pteridophyta, it must not be supposed that they are 

 necessarily homologous. Indeed, in his studies on the 

 spore-producing members, Bower gave reasons for hesi- 

 tating to adopt the view without reserve. He held that the 

 so-called sporophylls of many of the latter are not neces- 

 sarily foliar structures, but may be traced to development 

 from outgrowths similar to the sporangiophores of Helmin- 

 thostachys. He said, ' the practice of referring every 

 part of the shoot to some modification of axis or leaf, 

 emergence or hair, has already been broken down in the 



