80 POPULAE EEROES. 



however, ■will cover all cases. First, defective 

 ovules; second, want of fertilization. 



Usually, when pollen is withheld no fruit what- 

 ever comes to maturity. But there are some ex- 

 ceptions to this rule. The Date frequently produce 

 fruits when no pollen-bearing plant is near; but 

 always in such cases without seed. In the artificial 

 fertilization of plants it frequently happens that 

 where little pollen is applied few seeds are pro- 

 duced. It is probable that most cases of seedless- 

 ness are due to lack of pollen, these fruits having 

 the unusal power of attaining more or less com- 

 plete development without it. 



There are other cases where seedlessness is not 

 due to any want of pollen but to defective ovules. 

 This often rises from excessive vigor of growth 

 and probably in some cases to abortion of the 

 ovules or rudimentary seeds. Hybrids, which are 

 sometimes remarkably vigorous, are often partially 

 or wholly seedless. The somewhat abnormal fruits 

 of certain varieties of the orange are partly or 

 wholly seedless. The pods of double flowers, if 

 formed at all, are apt to have few or no seeds. 



Seedlessness, though not fully understood, is 

 probably not beyond the reach of being under 

 stood, but can doubtless be explained in a reason 

 able manner by sufficient study. 



