600 



Sir John Lnhhoch 



[Feb. 18, 



In other cases the plant throws its own seeds to some little distance. 

 This is the case with the common Cardamine hirsuta, a little plant — I 

 do not like to call it a weed — six or eight inches high, which comes up 

 of itself abundantly on any vacant spot in our kitchen-gardens or 

 shrubberies, and which much resembles that represented in Fig. 17, 

 but without the subterranean pods h. The seeds are contained in a 

 pod which consists of three parts, a central membrane, and two lateral 

 walls. When the pod is ripe the walls are in a state of tension. The 

 seeds are loosely attached to the central piece by short stalks. Now, 

 when the proper moment has arrived, the outer walls are kept in place 



Fig. 2. 



Viola hirta. 

 a, young bud ; h, ripe seed capsule. 



by a delicate membrane, only just strong enough to resist the tension. 

 The least touch, for instance a puff of wind blowing the plant against 

 a neighbour, detaches the outer wall, which suddenly rolls itself up, 

 generally with such force as to fly from the plant, thus jerking the 

 seeds to a distance of several feet. 



In the common violets, beside the colored flowers, there are others 



