ORGANS OF NUTRITION. 



131 



upwards and downwards (^ftg. 249). The common Radish 

 {Raphaims sativus); and the Beet {Beta vulgaris) msiy be taken 

 as examples of this form of root. 



Napiform or Turnip-shaped Root. — This name is given to a 

 root which is much swollen at its base, and tapers below into a 

 long point, the whole being of a somewhat globular form {fig, 

 250). It occurs in a variety of the common Eadisli, Avhich is 



Fig. 249. 



Fig. 250, 



Fig. 251. 



Fig. 251. P]acentiforiii root. 



Fig 249. Fusiform root of the common Radish. • 

 root of the Turnip. 



Fig. 250. Napiform 



hence called the Turnip-radish ; in the common Turnip {Bras- 

 sica Napus) and other plants. When what would be other- 

 wise a napiform root becomes compressed both at its base and 

 apex so that it has no tapering extremity, it is said to be placen- 

 tiform {fig. 251). It occurs in the* Sow-bread {Cyclamen 

 europceum). 



The recent researches of botanists have shown, that the so- 

 called roots of the Radish, the Turnip, the Cyclamen, and 

 probably some others, are really enlarged stems. We have, 

 however, placed them here with the roots, in accordance with 

 the commonly accepted views of their nature. 

 k2 



