90 



THE STRUCTURE OF FLOWERS. 



T^Taudln, Ph. Van Tieghem, and, I tliink, Englisli botanists in 

 general.* 



There are three methods of investigation, which conjointly 

 may guide us to the discovery of the real natui-e of the tube. 

 The first is that of following its development ; the second 

 is teratological, and the third anatomical. 



Morphological Investfgations. — In tracing the morpho- 

 logical development of flowers of the Eosacece, where the 

 receptacular tube is a characteristic feature, one notices how 

 a border, surrounding the domelike ternaination of the axis 

 which soon produces carpellary papillse, rises upwards and 

 elevates the sepals and the papillae of the petals and stamens. 

 This border ultimately forms the tube ; and the question is, 

 whether it should be regarded as the basal part of the calyx 

 or a development from the axis. 



In the Pomeoi we find the apocarpous condition of the 

 pistil, characteristic of all the other members of the Bo^acem 

 still retained at first ; but in consequence of the growth and 



close proximity of the tube 

 Avith the carpels, various 

 degrees of adhesion are 

 brought about between 

 them ; thus, in Fyriis (Fig. 

 22, a), the bases only of 

 the carpels are from the 

 first fused into the axis. 

 In Gotoneaster (6) the fusion 



Flff. 22. — a, Pijrus ; b, Cotoneaster fafter Paj-er). . n . i • i i i 



^ . i/ ' . >. 1 J extends to a higher level 



on the ovaries. Such " half-inferior " ovai-ies occur in 

 other genera, as Saxifraga granulata, Gloxinia, etc. From 

 such we pass to completely inferior states, as in Compositce 



* Benthain and Hooker describe the inferior ovary of the Pomece 

 in the terms, " Calycis tubus ovario adnatus." 



