THE FLOWER BEHAVIOR OF AVOCADOS 



151 



reveal the general rules of the normal flower-behavior during the 

 hours between sunrise and sunset in a single day. 



1. For all varieties there are two different sets of flowers 

 open during the day. The flowers of one set function as females, 

 those of the other as males. Each set opens and closes in unison 

 and the two sets are open during different hours of the day. 

 While there is frequently a short interval of overlap of the two 

 sets during the shift in midday, the rule is that no pollen is shed 

 while flowers in the female condition are open. Pollen is lacking 

 for a time after flowers open for the second period and then it is 

 scant for a time. Later the maximum of pollen shedding is 

 reached after which pollen again becomes increasingly scarce. 

 Unless pollen is carried away by insects the masses of pollen 

 harden and become dried into little balls that fall to the ground. 

 It seems most probable that the pistils are not fully receptive 

 for fertilization during the entire time flow^ers are open for the 

 first period and that a line representing their most receptive con- 

 dition Avould be much shorter than is shown in the various charts. 

 But considering the entire periods of opening, in every case the 

 synchronous alternation of sex most decidedly limits self- and 

 close-pollination. 



2. The varieties fall into tAvo groups which reciprocate with 

 respect to the relative sequence of the daily alternation in the 

 development of the two sexes. The members of one group are 

 female in the forenoon and male in the afternoon while the mem- 

 bers of the other group are male in the forenoon and female in 

 the afternoon. 



List of the most important varieties according to the 



A. Varieties that normally have flowers open for the first or 

 female opening in the forenoon and flowers open for the second 

 or male opening in the afternoon : 



DAILY sequence OF DIANTHESIS 



Atlixco 

 Baker 



Butler 

 Cantel 



Challenge 

 Glower 



Dickey 



El Presidente 



Family 



Gottfried 



Baldwin 

 Benik 



California 

 Trapp 



Colorado 

 Dickinson 



