AGRICULTURAL EXPERIMENT STATION. 53 



pollen applied, appears to have little effect in regard to this 

 point. 



In general, while little accurate work has been done in the way 

 of determining the exact amount of pollen necessary for fertiliza- 

 tion, it appears that the question has bearings of much practical 

 importance. In some instances the size of the fruit seems to be 

 in direct proportion to the amount of pollen used, while the form 

 is much improved by an abundant supply. In some cases, on the 

 other hand, fruits will develop without the intervention of the 

 male element, and the best results are obtained when pollen is 

 withheld. 



IV. On the General Influence of Foreign Pollen, and 

 Other Miscellaneous Observations. 



As already intimated, pollen appears in many cases to act direct- 

 y on the ovary, stimulating growth of that organ independently 

 of any effect on the ovules. This fact is most clearly seen in 

 those species which do not readily cross. 



In this connection, Focke remarks: "The pollen of the 

 species acts quicker than foreign pollen and is alone effective if 

 mixed with foreign pollen upon the stigma. * * * It is 

 probable that if the pollen of the species is insufficient, foreign 

 pollen may serve to develop the fruit, and thus serve a purpose."* 

 Some instances strongly supporting this pi'oposition have come 

 under my observation. 



One of the large English cucumbers, " Duke of Edinburg," was 

 given pollen of the " Emerald Gem" muskmelon. The cross was 

 made in February. The resulting fruit attained about one-half 

 the normal size and then ceased growing. "When the vines vrere 

 torn from the house in June, this fruit was still green while other 

 fruits, receiving pollen of the species two months later, were fully 

 mature. The ovules in the fruit in question were wholly undevel- 

 oped. 



Two other instances of a similar nature were observed. The 

 first of these was the common Summer Crookneck squash crossed 

 by the American Turban — Figure 15 ; while the second was the 

 same variety crossed by Mammoth Tours pumpkin — Figure 16.| 



*Die Pflanzen michlinge, 448. 



fThe two crosses last named were made by Professor L. H. Bailey at Cornell 

 University. All other illustrations ai-e Irom work performed by tbe writer. 



