Propagation of Onions 317 



bulbs are of three kinds: ^^top onions,'' or bulblets that 

 are produced on the top of the flower stalk, in the place 

 of flowers; ^^sets" (Fig. 91), which are small onions, 

 arrested in their growth; "potato onions," or "multi- 



F\g. 90. Onion seedlings. Natural size. 



pliers," which are compound bulbs, each component part 

 forming a new bulb- The top onions (sometimes called 

 "tree onions") and the multipliers are distinct races or 

 types of onions, but sets are only the partially grown 

 bulbs of any common onion which it is desired to propa- 

 gate in this way. To raise sets, seeds are sown very 



