Fink: lycopersicum esculentum. 637 



twenty- four hours and the last third immediately after castra- 

 tion. At the end of twelve hours the styles were removed 

 from one third of each lot; at the end of eighteen hours the 

 second third were treated in the same way; and at the end of 

 twenty-four hours the remaining third. The number of hours 

 intervening between pollination and removing the style was 

 marked on each card. The markings on the cards were 1-12, 1-18, 

 1-24, 2-12, 2-18, 2-24, and 3-12, 3-18, 3-24, and there were of course 

 three cards for each marking. The tomatoes which matured 

 bore the following cards; 1-12, 1-12, 1-18, 1-18, 1-24. 1-24 1-24, 

 2-24, 2-24, 3-24-. Thus twelve hours was found to be long 

 enough for the pollen -tube to pass through the style in most 

 cases when the stigma was mature when pollinated. Later, 

 I tried six and nine hours, allowing forty-eight hours to inter- 

 vene between castration and pollination. No fruit developed 

 in the last two experiments. 



Some very interesting experiments were tried to ascertain 

 how much care must be used in order to get the pollen on the 

 stigma at the proper time. Two questions of interest arise. 

 One is the length of time that the stigma is in such condition 

 that pollen placed on it will be effective. I found the time to 

 be longer in large flowers than in smaller ones and longer in 

 monstrous flowers than in normal ones. I suppose this is be- 

 cause it takes the large pistils longer to reach maturity and 

 begin to wither. The time must be counted from the moment 

 the bud opens enough to expose the pistil, which is usually 

 protruded somewhat beyond the stigma. The stigma is not in 

 the best condition for holding the pollen at this time, but a 

 sufficient amount adheres, is more effective and passes through 

 the style sooner than when placed on the stigma later. This 

 was very evident in a case in which the stigmas were pollinated 

 as soon as the flowers had been castrated and before the an- 

 ther-cells had opened. The number of tomatoes produced was 

 larger than from flowers pollinated when the stigma was more 

 mature, and the ovaries began to enlarge sooner than in cases 

 in which flowers of the same age were allowed to stand longer 

 for the stigmas to get in better condition for pollination. Pol- 

 len placed on the stigma past prime makes very slow work if 

 effective at all. Counting in the way indicated above, the time 

 is from four to eight days, and during the first day or two the 

 flowers cannot be close-pollinated as the pollen-sacs are not 

 yet open — an arrangement favoring cross-pollination. 



