I5I2 A TEXTBOOK OF THEORETICAL BOTANY 



The second example is EcboUium elaterhim, the Squirting Cucumber 

 (Fig. 1382), a member of the Cucurbitaceae with oblong, green fruits about 

 2 inches long. It is native to the Mediterranean area but it is to be found in 

 many warmer parts of the world, usually in dry places, climbing or spread- 

 ing prostrate on the ground. The end of the pedicel forms a plug in the base 

 of the fruit, the connection between them breaking down as the fruit 

 ripens. Inside the fruit is a number of oval, flattish seeds, surrounded by 



Fig. 1382. — EcbaUium elaterium. Shoot with 

 ripe fruits, about natural size. 



mucilaginous fluid. In the wall of the fruit is a layer of highly osmotic 

 cells which are under compression. A shght touch loosens the connection 

 with the pedicel and the fruit jerks off, the compressed cells expand and 

 the seeds and the sticky fluid are shot out of the basal opening with great 

 force, flying as much as 20 ft. away (Fig. 1383). Indeed it is a feature of 

 many of these mechanical methods of seed expulsion that the seeds are 

 adhesive and so are capable of being additionally dispersed by animal 

 carriage. 



Wi7id Dispersal (Anemochory). Wind is undoubtedly the most general 

 agent of dispersal both of seeds and fruits. It is not essential that the seed 

 should possess obvious accessories for wind dispersal, such as wings or 

 plumes, for strong winds are capable of blowing even heavy seeds for con- 

 siderable distances while they are dropping from the plant, or even of 

 rolling them along while they lie on the ground. This leaves out of account 

 exceptional occurrences like whirlwinds, which are capable of lifting and 

 carrying quite large and bulky objects, though such storms are common 



