626 



Journal of Agricultural Research 



Vol. XII, No. lo 



Table IV. — Relationship between flower position and the degree of setting in hermaphro- 

 ditic and pistillate varieties of strawberries 



" Not certainly true to name. 



The most characteristic type of nubbin is that in which all of the 

 achenes set except those situated at the tip, thus, producing a berry 

 with a dead, dry tip. This raises the question as to why the tip pistil 

 should be more sterile than those at the base. 



We have already seen that when a reduction in stamen number takes 

 place it is the youngest which are lost first, and apparently this is true 

 also of the pistils. The pistils of the oldest flowers are decidedly more 

 fertile than those of the later flowers, and it seems logical that the older 

 pistils Avithin a flower should be the more fertile. Observations on a 

 seedling everbearing variety which in the spring produced only stamens 

 and a small, white dome destitute of pistils in place of the ordinary 

 receptacle, but which later in the season gradually produced normal 

 flowers, illustrates this point. It was noticed that the first flowers which 

 produced pistils developed only a few normal ones around the base of 

 the receptacle, while those above gradually decreased in size until at 

 the tip there were none. The later fruiting stalks increased the number 

 of normal pistils until in the last fruiting stalks the entire receptacles of 

 the first flowers were covered with normal pistils. This series of flowers, 

 although an extreme with regard to sterility, still indicates the portion 

 of a flower in which there is the greatest likelihood of its appear^ance. 

 The question of pistil sterility should be kept in mind in the selection 

 of breeding stock, as it is most certainly inherited in the pure species 

 and apparently is in the cultivated varieties, as selfed seed of Glenville, 

 a variety which rarely sets more than an occasional primary flower. 



