CH. IX] DIVERGENCE OF VARIATION 75 



two extremes. For instance, among the characters will be found 

 the following: 



Root tap or adventitious 

 Stem monopodia! or sympodial 

 Leaves alternate or opposite 

 simple or compound 

 palmate or pinnate 

 parallel or net veined 

 Inflorescence racemose or cymose 

 Flower spiral or cyclic 



mon- or di-oecious 

 iso- or hetero-merous 

 regular or zygomorphic 

 Receptacle above or below calyx 

 Parts of flower in 2s, 3s, 4s, 5s, etc. 

 Calyx in one or two whorls 

 Odd sepal anterior or posterior 

 Corolla free or united 



imbricate, valvate, or convolute 

 alternate with, or superposed to, sepals 

 Stamens in one, two, or more whorls 



diplostemonous or obdiplostemonous 

 free or united 

 Anther versatile or not 



opening by slits, pores, valves, etc. 

 Pollen in various patterns of cell wall 

 Carpels free or united 



1 to 00 



transverse or anterojDOsterior 

 Placentation parietal, axile, etc. 

 Raphe ventral or dorsal 

 Micropyle up or down 

 Style basal or terminal 

 Stigma capitate or lobed 



Fruit achene, follicle, capsule, drupe, berry, etc. 

 Seed with or without endosperm 



one, few, or many 

 Embryo straight, curved, twisted, etc. 



and many more equally divergent, whilst in the few cases where 

 intermediates are possible, no functional value or disadvantage 

 can be read, either into them or into one of the extreme diver- 

 gents. In no case, in these family characters, has any functional 

 value been shown, in a definite and unmistakable manner, 

 though suggestions have been made in one or two cases. 



If now one go on to the characters used in the keys which 

 determine the genus and species of a plant belonging to one of 



