68 FAMILIAR TREES 



clearness and cheerfulness of tone that it loses later 

 in the year. The leaves, which are in opposite pairs, 

 consist of two, three, or four pairs of broadly egg- 

 shaped, serrated leaflets, and a terminal one, each of 

 which seldom exceeds three inches in length. The 

 small creamy-Avhite flowers form an erect and 

 singularly flat " cymose " inflorescence, sometimes 

 nearly a foot across, which is especially characterised 

 by having five principal radiating branches. 



Even in a wild state this tree exhibits a consider- 

 able tendency to vary, a disposition which naturalists 

 have been but too apt to ignore in the subjects of their 

 study. Thus the number of the leaflets is sometimes 

 reduced to three, and they are almost round in out- 

 line ; at other times their edges are much notched ; 

 or, again, they are more or less completely variegated 

 with yellow or white, whilst the usually black fruit 

 is occasionally green or white when ripe. Though, 

 perhaps, an escape from cultivation, as it certainly is 

 generally in this country, we have noticed the cut- 

 leaved variety to be very frequent in the hedgerows 

 of Belgium. 



Such plants, with divided leaves, densely clustered 

 small white flowers, and juicy fruitlets, suggest many 

 ideas as to the probable causal or purposive signifi- 

 cance of their structure. One sees at once a connec- 

 tion between the arrangement of the branches (two of 

 which spring from the stem in the " axils " of a pair 

 of " opposite " leaves, while the next pair are given 

 off at right angles to them, or " decussately ") and 

 that of the paired leaflets in the " pinnate " leaf. The 

 relations between the veins, or rather the skeleton, of 



