FRUIT FORMATION 487 



depending on conditions, and an almost negligible June drop. When 

 Llewelling is grown under similar conditions it usually shows a fairly- 

 heavy first drop, a light second drop and a very heavy June drop. 



It is interesting in this connection that occasionally certain flowers 

 of the cluster do not set well, while others set fruit perfectly. Schuster^^^ 

 has called attention to this peculiarity in the flower clusters of Ettersburg 

 121, a strawberry variety. The primary flowers of the cluster, those com- 

 ing from the forks, set freely; only a small percentage of the secondaries, 

 those coming from the lateral branches of the peduncle, set fruit. The 

 case is not exactly one of blossom dropping, for the flowers do not drop 

 off; but it is at least in certain respects comparable to the first drop 

 described by Dorsey for the plum, though the pistils do not appear to be 

 defective. Valleau^^^ found in some species and in certain varieties of the 

 strawberry that the later flowers to open may have sterile pistils. He 

 ascribes this to a tendency toward dioeciousness. 



Another interesting case of the June drop or of a pheuomenon comparable 

 to it is found in the date pahn. Ordinarily by the end of June three partly 

 grown fruits of approximately equal size have developed from the three ovaries 

 of each pistillate flower. If pollination and fertilization have taken place two of 

 these developing fruits drop off, leaving a single one to mature. On the other 

 hand, if the flowers have not been pollinated, all three may persist and continue 

 to grow slowly; they never reach full edible maturity and are without value. 

 They are seedless, closely crowded together and generally somewhat deformed. ^^"^ 



Fruit Setting, Fruitfulness and Fertility Distinguished. — In the 



preceding discussion the term "fruit setting" has been used to refer both 

 to the initial setting of the fruit at or just after the time of blossoming 

 and to its remaining on the plant until maturity. The term is used often 

 in a somewhat narrower sense to indicate whether or not it remains 

 attached to the plant for any considerable time after flowering and whether 

 any enlargement of the ovary takes place. Probably in the case of the 

 plum just described in detail few would regard the fruit as having 

 set if it did not siyvive the second drop, but many would consider it as 

 having set if it remained through this period, even though abscission 

 took place at the time of the third or June drop. There are reasons for 

 refraining from an attempt to limit too closely the meaning and use of the 

 term. However, it is desirable to be able to refer to definite conditions 

 that are exemplified in many different species. By common consent the 

 term "fruitful" is used to describe the plant that not only blossoms and 

 sets fruit, but carries it through to maturity. The plant that is unable to 

 do this, or that does not do it, is "unfruitful" or "barren." "Fertihty" 

 indicates ability not only to set and mature fruit but to develop viable 

 seeds. Inability to do this is described by the terms "infertility" and 

 "sterility." Fruitfulness and fertility are not synonymous, for manj^ 



