EXPERIMENTAL EMBRYOLOGY 



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effective. Ilex opaca was used for most of the experiments, partly 

 because of its dioecious nature and partly because of its broad 

 stigma, which tends to facilitate diffusion. Considerable success 

 was achieved in obtaining seedless fruits in this plant. Some posi- 



Fig. 212. A, fruit production in Capsicum; left, from fertilized ovary; right, after 

 treatment of pistil with indolebutyric acid. B, fruits in Nicotiana; two on left, 

 from fertilized ovary; two on right, after treatment of pistil with potassium salt of 

 indoleacetic acid. An unfertilized and untreated pistil is shown in the middle. 

 (Photographs supplied by Dr. F. G. Gustajson.) 



tive results were also obtained with strawberries but none with 

 apples and pears. 



Similar experiments were soon undertaken by other workers, and 

 a few studies have also been made on the comparative histology 

 and vitamin content of normal fruits (resulting from pollination) 

 as well as parthenocarpic ones (resulting from hormone treatment). 



