THE FAMILY CHAIN 357 



classification the history of the science illustrates; yet progress is 

 in the direction of stal)ility, and certain chains,- having held from the 

 first, bid fair to endure. The integrity of tlie Ranunculacea?, for 

 example, seems assured in spite of the witle divergence of its extreme 

 forms and in spite of the difficulty of defining its limits. 



We have now to define the family as best we can. The generic 

 formulas will help us to a formula for the family and this in turn will 

 lead us to our definition. Taking the prevailing characteristics 

 of each part as typical for the family, and neglecting the less sig- 

 nificant exceptions to the general rule, we may express a generalized 

 view of the salient features as shown in the formula of Ranunculacese 

 on pages 404, 405. 



The only invariable features here expressed are the anatropous 

 ovule and the uncoiled embryo surrounded by albumen, and these 

 as we shall see are common to a number of other families. But, as 

 we shall also see in comparing the Ranunculacese with other groups, 

 it lacks features which they possess. 



Taking into account all the facts we have learned, the 

 crow^foot family may be described as consisting of herbaceous 

 or rarely w^oody plants, never trees, without milky juice, oil 

 or other secretions in special reservoirs, but with a mostl}' 

 colorless and odorless sap which is generally acrid, and in 

 some cases renders the plant poisonous to eat or to touch; 

 leaves mostly palmately branched, or at least palmately 

 ribbed; flowers mostly regular and perfect with the parts 

 free and cUstinct (with rare exceptions) ; sepals commonly 

 five, generally petaloid; petals rarely present, often replaced 

 by more or less petaloid staminodal nectaries of widely 

 differing forms; stamens generally numerous; anthers de- 

 hiscing by slits; pistils almost always simple, numerous, 

 few, or rarely solitary; ovules anatropous, many, few or 

 solitary, sometimes rudimentary; fruit follicular, capsular, 

 achenial, or rarely fleshy; the seeds with hard albumen sur- 

 rounding a minute uncoiled embryo. Or, if we disregard all 

 that is untj'pical, it may be said that whenever we find an 

 herb with the juice colorless and scentless, the flowers having all 

 their parts distinct and free, sepals about five, and essential 

 organs numerous, we may be tolerably sure that our plant is 

 one of the crowfoot family, although some departure from 

 these characteristics would not necessarily exclude it from 

 the group. 



