APRIL. 85 



Uncinia might be distributed by ground birds, but the fact 

 already stated as to the tendency in the former plants to 

 disappearance of the barbs shows that the method is not 

 very effective. 



Another very common and effective mode of seed- 

 distribution has been much in evidence during windy 

 weather recently. Many plants develop their fruits or 

 seeds (the terms in many cases are used somewhat 

 indiscriminately) in such a way as to be caught and borne 

 along by the wind. Willows, some poplars, willow-herbs 

 (Epilobinm), and that common white - flowered bush 

 climber Parsonsia, have small seeds furnished with tufts of 

 hair, so that when the seed vessels open and set their 

 contents free the little seeds float away on the slightest 

 breeze, each borne on its own little parachute. In the 

 Clematis each fruit has a long feathery style acting in the 

 same way. An almost identical device occurs in the fruit 

 of the great order of Composites, an order containing some 

 10,000 or 12,000 species of plants, in a great number of 

 which (exemplified by thistles, dandelion, groundsel, etc.) 

 the tube of the calyx develops into a crown of hairs or 

 bristles the so-called pappus by means of which the 

 fruit is carried on the wind. It is in great part owing 

 to this exceptionally good mode of scattering their seeds 

 that Composites are not only the most numerously 

 represented, but also the most widely distributed, of all 

 orders of flowering plants. Their nearest allies, the 

 scabious or pincushion flowers and the valerians, are 

 much more limited in their range. 



Into the gutters and sides of footpaths, where dust loves 

 to congregate, the wind has during the last few weeks 

 swept many of the winged fruits of the maples and ash 

 trees. The latter tree has a single nut bearing a long flat 

 expansion of its outer covering which acts like the sail of a 

 windmill, while maples have usually twin nuts with 

 spreading sails. On a breezy day they go whirling along 

 in the air till they come to rest in some damp or sheltered 

 spot, where they promptly commence to grow. Natives as 

 they are of Northern Europe, where the winters are 



