298 FREAKS OF PLANT LIFE. 



A like provision may be observed in the willow- 

 herbs (Efilobium), and in many of the Apocynacea, 

 as well as the Asclepiadacece. Yet this is only one 

 provision for the dispersal of seeds by the agency of 

 the wind. Another, and equally successful contriv- 

 ance is the expansion of the sides of the seed into a 

 membranous wing. These winged seeds reach their 

 highest development in the trumpet flowers {Big- 

 noniacece), where the large wings extend three or 

 four inches, and the seeds float like a large butterfly, 

 wafted from place to place, until a secure home is 

 reached. In our own country such winged seeds 

 are usually minute, if we exclude the heavier and 

 less delicate winged fruits of such trees as the maple, 

 ash, and elm, which are called samarcz. These 

 latter are doubtless aided in their dispersion by 

 means of their wing-like margins, to which we shall 

 have occasion to refer again hereafter, when writing 

 of the similarities which prevail in the organs of 

 very diverse plants. We are justified, then, in assert- 

 ing that special provision is made for the dispersion 

 of many seeds through the air, by means of the wind. 

 Spiny fruits are found amongst the members of 

 many of the families in the vegetable kingdom: It 

 is evident that the rigid spines with which they are 

 armed aid considerably in their dispersion. The 

 name of "caltrops" has been applied to some of 

 these, in allusion to the "calcitrapa" which was 



