38 



DICOTYLEDONS 



caused to spill their pollen on the insect which now with a new 



load of pollen flies to another flower. Now, 

 as the wings and the keel of the flower are, 

 by a sort of joint at their base attached to one 

 another very closely and firmly, it requires 

 considerable strength to press them down so 

 as to get at the honey in the interior. Not 

 all insects have the strength necessary to do 

 this. Bees are strong enough to overcome all 

 the difficulties on their way to the honey, and 

 it is chiefly by them that these flowers are 

 fertilized. Some of them, it is true, try to 

 get at the honey by a shorter way. They 



break in like thieves and bite a hole through 



Fig. 3 7. — Legume 



of the Pea. 

 c. Calyx, s. Seeds. 



r. Midrib. 

 h. Ventral suture. 



the flower-leaves at the base. 



5. The Fruit (fig. 37) is a pod or legume, 

 consisting of a single carpellary leaf, which 

 is folded inwards in its midrib having the 

 edges seamed together (ventral suture). The 



pod contains several seeds in one row, all 



attached alternately to the two edges of the 



seam of the fruit-leaf which form the concave 



edge of the legume. The calyx remains 



attached to the fruit and is, therefore, called 



persistent. The point of the pod, more or 



less withered, is, of course, the style of the 



flower. Wlien ripe, the legume splits both at 



the midrib and at the seam, thus dividing 



into two halves. There are various modifica- 

 tions of this typical legume in other genera 



of the Leguminosa\ The legume of Pomjamia 



is indehiscent (not splitting) and one-seeded; 



tliat of Hmithia and Desmodium jointed and 



when ripe dividing into its separate joints; 



Butea and Ddlherfjla liave winged legumes; 



and Crotalaria inllatod ones, etc. 



Fig. 38. — Legume of 

 Buten frotidosa 



