in the Inflorescence of Zea Mays. 



216 



it is difficult to understand why it should be so — the female 

 organs in this instance, as indeed in most other unisexual 

 plants, are much less prone to become developed in the 

 male flowers than are the male organs in the female flowers.* 

 On this account, then, I trust the Society will bear with 

 me while I briefly attempt to describe the few male monoi- 

 cous panicles, which I have been fortunate enough to ob- 

 tain ; they are as follows : — 



First, In specimen No. 2, — a terminal panicle, — the pri- 

 mary axis bears male and female florets ; the florets of 

 the former are perfect in the upper portion of the axis, 

 which they exclusively cover, but in the lower portion, 

 where they approach the female florets, the superior floret 

 in the majority of the spikelets is alone perfect ; while 

 in the inferior floret the stamens occur in a more or less 

 rudimentary condition. The female florets of the primary 

 axis are all imperfect, the ovary existing in a rudimentary 

 form, and the stamens utterly aborted in the superior 

 florets ; whereas, in the inferior florets of the spike- 



^ May we not regard this as probably indicative of those homological dis- 

 tinctions between the male and female organs of plants, insisted upon by 

 Schleiden and Endlicher, at least as modified by Dr Dickson, in his interesting 

 paper " On the Nature of the Cormophyte." [Vide Society's Transactions, 

 vol. vi. p. 95.) Dr Dickson there states, that he is " inclined to believe that 

 there exist in reality two modes of placentation, the one where the ovules 

 are produced by a process of gemmation from the carpellary leaves {parietal) ; 

 the other, where the ovules spring from the prolonged floral axis {central). 

 In this modified sense, then, a strong argument against the Schleidonian 

 theory of placentation is completely neutralised. I refer to the inverse con - 

 vertibility of male and female organs in certain plants. For example, in the 

 willows, we have some excellent illustrations in the Society's Transactions. 

 Thus, in vol. i. page 113, the Rev. J. E. Leefe has illustrated the gradual 

 modifications of the pistillary into staminal organs in the Salix Caprea ; while 

 Mr Lowe, vol. v. p. 113, has given us, vice versa, all the conceivable interme- 

 diate stages in the transformations of the staminal into the pistillary organs 

 in Salix Andersoniana. Now, as these cases of the willows naturally come 

 under the division assumed to possess a parietal placentation, their evidently 

 disproving tendencies are utterly invalidated. And thus, even in view of 

 such anomalous occurrences, we may justifiably reiterate the above sugges- 

 tion, as to the difference in the inverse convertibility of the male and female 

 organs, in at least the case of the maize, where the floral axis, as terminal 

 shoot, undistinguishable in the cavity of the germen as a special organ, bears 

 a single seed-bud (Schleiden's " Principles of Botany," p. 386), and is thus 

 referrible to the division characterised by a central placentation. 



