FERTILIZATION AND CROSS-FERTILIZATION. 77 



ject has a practical side, of much interest both to seed growers and 

 seed planters. 



The Chau'man inquired whether any one had any facts to present 

 in regard to fertilization under glass. 



F. L. Harris replied that he had had some success in crossing 

 Draccenas. He had fertilized Mooreana, a species having a self- 

 colored, deep bronze leaf, with regiria, and produced twenty-five 

 plants of which no two were alike, and all partook of the properties 

 of both parents. One of them had a leaf larger than that of either 

 of its parents, and several of them were really superior to either 

 parent. Mr. Butler, gardener at "Wellesley College, has crossed 

 regina and terminalis stricta, and the progen}^ was much superior to 

 Mr. Harris' seedlings. These were both variegated kinds, instead 

 of a self and a variegated, and more vigorous, yet he produced 

 pigmies, which made most beautiful table ornaments. Mr. Harris 

 operated artificially, first removing the stamens, which he believed 

 to be the true way. He had found Draccena congesta fruit readily, 

 while other species do not ; the congesta may have been fertilized 

 by insects, and yet this is doubtful, for it fruited in winter when no 

 insects were around. Tropical plants do not fruit readily in green- 

 houses ; he did not believe that a cucumber ever fruited under glass 

 without artificial aid. He thought that grapes had the power of 

 fertilizing themselves so as to produce fruit, but European gar- 

 deners declare that it is necessary to syringe the Muscat. He 

 thought the failure to produce fruit under glass might be owing to 

 the absence of insects. 



Mr. Hovey said that a breeze was needed to start the pollen. As 

 a general rule the house is kept rather close. The Muscat of Alex- 

 andria grape requires heat to burst the anthers. He did not think 

 that each fiower would fertilize itself. 



Mrs. Wolcott said Mr. Hovey's remarks implied that cross- 

 fertilization would be produced b}- the current of air. 



Mr. Wetherell alluded to the danger of cross-fertilization among 

 plants of close atBnity, as the cabbage, squash, and other families. 

 Darwin planted a white kohl-rabi, a purple kohl-rabi, a Ports- 

 mouth broccoli, a Brussels sprout, and a sugar-loaf cabbage near 

 together and left them uncovered. Seeds collected from each kind 

 were sown in separate beds ; and the majority of the seedlings in 

 all five beds were mongrelized in the most complicated manner, 

 some taking more after one variety and some after another. The 



