74 TURNIP DISEASE. 



(296 ) The plant attacked which is next in importance 

 to the potatoe is the common white turnip. In this case 

 the perfect insect commences its attacks by settling upon 

 the larger leaves of the turnip when the plant is about four 

 inches high, and there producing its young. Sometimes, 

 however, it attacks it at an earlier period of its growth, 

 even when in the seed leaf; and I have this day observed 

 it in the Circus garden on plants barely out of the seed 

 leaf. 



(297.) These young ones continue to produce with great 

 rapidity, and spread from leaf to leaf, until the whole plant 

 is implicated. The larger leaves which were first attacked 

 die first, and the others in succession, till the whole plant 

 becomes disorganized. 



(298.) Sometimes the plants affected present a curious 

 appearance at the root, called "fingers and toes;" in fact 

 the root becomes diseased, and these fingers and toes are 

 multiplications of the root, and are thrown out by an effort of 

 nature in order to compensate for the injury'done to the main 

 root or turnip. In this state the turnip dies, becomes with- 

 ered and dried up, forming an example of gangrena sicca, 

 analogous to the dry gangrene of the potatoe. 



(299.) The manner in which the turnip dies is quite 

 similar to that in the case of the potatoe ; a portion of the 

 leaf may go, a portion of the stalk supplying nourish- 

 ment to the plant may die, or, lastly, the root or whole 

 plant may perish. 



(300.) If the bulk is fully formed, and the insects con- 

 tinue to prey upon the leaf, the collar of the turnip, that is, 

 the joining point of the leaves and the root, begins at last to 

 rot, and after the lapse of a short time, if the leaves are 



