346 



KNOWLEDGE & SCIENTIFIC NEWS. 



[February, igo6. 



of investigation, however, will prove that these com 

 plicated and highly specialised organs have a leal 

 ancestry just as much as any other part of the flower. 

 In a general way, although the stamens of the flowei 

 are, in the case of double blossoms, sacrificed to make 

 up the additional petals, the pistil is in a more or less 

 perfect condition. But there is just one double flower 

 which lets a good deal of light on to the question of 

 the origin of the pistil. This is the double Cherry, a 

 flower which it will well repay anyone who is intereste<l 

 in the matter to study a little closely. If the inner 

 petals of a well develojsed bloom of the double Cherry 

 are torn away it will be found that almost invariably a 

 tin\' leaflet occupies the centre of the bloom. This 

 little leaf, it will be noticed, is exactly in the place of 



possible to see small projections on the borders of this 

 curiosity (which may he called the carpellary leaf) that 

 show where, under ordinary conditions, the ovules 

 would have been. 



In the present and the preceding article all the differ- 

 ent parts of the typical flower have been detailed in the 

 order in w liich they occur when a start is made from the 

 outside and one proceeds inwards. This method has 

 been carried out as the simplest way of dealing with a 

 rather difficult subject. To the reader who has followed 

 the argument from the commencement the connection 

 which each p:irt of the flower has with the other is very 

 apparent. In every instance one is brought back either 

 directly, or through some other organ, to the leaf as the 

 oriein of the whole flower. That the leaf was in exist- 



in the centre of each Double Cherry bloom is to be found a small green leaf. 



the solitary carpel, which is, of course, the distinctive 

 feature of the tribe. A comparison of this leaf with a 

 perfect carpel of the Cherry is interesting. It is easy 

 to see that the two sides of the small leaf represent the 

 ovary, whilst the elongated process can be none other 

 than the style. 



Later on in their history the carpels often develop 

 into very leaf-like organs. This is the case in the seed 

 vessel of the Pea, where it is discernible that the two 

 sides of the pod are not unlike the lobes of a leaf 

 joined together by a midrib. A rare and most 

 suggestive monstrosity is sometimes to be seen in the 

 case of the Pea pod. This comes about when the 

 ovules fail to develop and the two sides of the pod do 

 not close together in the normal fashion. On such oc- 

 casions the lobes of the pod are more than ever leaf-like, 

 not only in appearance, but actually in structure. It is 



ence prior to the blossom is, of course, an indisputable 

 fact, for whilst flowering plants can persist without 

 blooms, they could not live at all without foliage or its 

 equivalent. 



Concerning the very important question as to the 

 order in which the various parts of the flower were 

 evolved there has been a good deal of controversy. A 

 moment's consideration will be sufficient to show that 

 the first part of the flower to be formed could scarcely 

 have been the calyx, the next the corolla, and so on. 

 It is almost impossible to conceive that these particular 

 organs, which, after all, are only appendages, even 

 though they ser\-e a useful purpose, should have been 

 formed in advance of the essential organs. The main 

 object of the brightly-coloured corolla seems in every 

 case to be as a means of advertising the presence of the 

 stamens and pistil to the special agent which will under- 



