5O A MANUAL OF 



writings of other authors who have written 

 upon these subjects, our readers may desire to 

 know what proof we can present to sustain 

 them. Well, these are the principles upon 

 which we have worked for the past ten years, 

 during which time we have grown, annually, 

 hundreds of thousands of plants. Never, dur- 

 ing all this time, have we seen a single case of 

 club-root developed upon a plant which had 

 not first been mutilated in its roots by the cab- 

 bage maggot, and never have we discovered a 

 trace of the maggot in the roots of plants 

 which had not first been severely worked upon 

 by the flea-beetles. 



On the other hand, never have we had a 

 bed of plants severely attacked by the beetles 

 or fleas that was not subsequently injured by 

 the maggot ; and further, never have we yet 

 seen a maggot in the root, or the slightest ten- 

 dency towards the development of club-root, 

 on a plant, or plot of plants, which had been 

 absolutely protected from the flea-beetles. 

 Although strong, this of course is only circum- 

 stantial evidence. We have taken a lot of 

 these maggots from a bed badly infested with 

 them, put them into a glass cage, and kept 

 them until they developed into perfect little 



