AGIilCULTURAL EXPERIMENT STATOTN. 33 



intense if fertilized by pollen from white varieties, than if self- 

 fertilized, or crossed by other dark varieties. That such influence 

 is doubtful, however, is indicated by the work of Goff, of Crozier 

 and others. 



In 1886, Goff crossed several varieties of black grapes with 

 pollen from a white variety — the Lady Washington. Other 

 flowers on the same vines were self fertilized. At maturity it was 

 impossible to detect any difference either of color or of flavor 

 between the self-fertilized and the crossed berries of the same 

 variety.* Similar results were obtained by Crozier at the Iowa 

 Experiment Station in 1888. f 



The cotton plant furnishes an instance in which there is appar- 

 ently unmistakable evidence of the immediate effect of foreign 

 pollen. In 1890, at the Georgia Experiment Station, flowers of 

 upland cotton, Gossypiuvi Barbadense, were crossed with pollen 

 from common Okra, Hibiscus esculentus. Apparently perfect bolls 

 of cotton were formed, but in every instance the seed failed to 

 germinate when planted. The reciprocal cross resulted in appar- 

 ently normal Okra seeds, but the offspring varied from the normal 

 in time of flowering and fruiting. | In 1891 the work was 

 repeated, and Director R. J. Redding in a private letter to the 

 writer reports, "bolls of cotton, the result of cotton blooms pol- 

 lenized with Okra pollen this year, in which one and sometimes 

 two of the carpels contained a very small quantity of lint adhering 

 to the seed while the other divisions of the ovary were abortive." 



It was early observed § that there is an immediate visible effect 

 of foreign pollen on corn, extending in many cases even to the 

 receptacle, and the repeated confirmations by Crozier, Sturtevant, || 

 Kellerman,^ Tracy** and others would leave little doubt as to the 

 accuracy of the observations. 



That there is a difference in varieties, in the readiness with 

 which the influence of pollen is shown, is altogether probable. 

 Sturtevant lays down the general proposition : "Under the condi- 

 tions of ordinary seed, maize does not in general show the effects 

 of current cross-fertilization, the exception being the sweet corns 

 which exhibit the influence of current foreign pollen very 

 readily." tt The proposition is based on the study of about one 



* 5th Rep. N. Y. Agr. Exp. Sta., 180. 



t Ag-r. Sci., 11,319. 



i Expt. Sta. Record, III, 135. 



§ Philosophical Trans., XLVII, 206. 



II 3rd Rep. N. Y. Exp. Sta., 148. 



IT 2nd Rep. Kan. Exp. Sta., 288-335, (1889). 



** Rep. Mich. Hort. Soc, 1888, 43. 



tt 3d Rep. N. Y. Ag. Exp. Sta., 149. 



