IV] MIXED INFLORESCENCES, ETC. 37 



Other cases of mixed and transitional inflorescences occur 

 in the Campanulaceae, Oleacege, Linaceae, &c. 



Examples of mixed inflorescences, which may begin 

 their branching as Racemes, Corymbs, &c., but the 

 ultimate ramifications of which pass over into Dichasia, 

 Polychasia, &c., are afforded by the following : 



Rub us Idceus Cratcegus 



R. fruticosus Apple 



R. Gcesius Pear 



Pyr'us Aria Rosa Canina 



P. Aucuparia R. ruhiginosa 



P. torminalis Ash 



P. Sorhus Horse-chestnut 



Privet Lilac. 



Certain special difficulties in the analysis of inflores- 

 cences are worth noting, as they can only be solved 

 by comparing allied species or by the study of develop- 

 ment. In the Vetches ( Vicia), for instance, all transitions 

 occur in the various species from typical racemes with 

 numerous flowers (e.g. V. Cracca) to short and few-flowered 

 racemes (F. gracilis) and axillary pedicels with only 

 two flowers (F. sativa) or even one (F. lutea), and 

 similar reductions occur in Ribes e.g. R. ruhrum and 

 R. nigrum have racemes, but in R. Grossularia these may 

 be reduced to two or even only one flower in the axil. 

 In the same way cymes are reduced to pairs of flowers 

 in Lonicera, and other cases occur in Violacese, Con- 

 volvulacese, Malvaceae, Geraniaceae, &c. A peculiar case 

 of especial interest to us is met with in the groups of 

 three or two or even one flower in the axils of the 

 catkin-scales in the Alder, Birch, Chestnut, Beech, Oak, &c. 



In other cases the inflorescence is complicated b}^ 

 the development of accessory fiower-buds, collateral or 



