106 Self-Inconqmtihility in Hermaphrodite Plants 



duction has been somewhat irregular but there has been no case of 

 decided increase in self-fertility as the plant progressed in bloom. Cases 

 showing the opposite condition have been found, but this was not known 

 in time to make tests to determine if all seed production was not also 

 decreased. 



Efforts have been made to test for end-season fertility, especially 

 in a line of red-leaved Treviso which has a somewhat shortened period 

 of bloom. In 1918, 10 plants, the first to flower in each of two series, 

 were thus studied. The plants that were completely self-incompatible 

 during the first ten days of bloom, in tests of about 30 flower heads, 

 remained completely self-sterile throughout. The only decided variation 

 in fertility observed in self-fertile plants was in the direction of a decrease. 

 Data may be given in detail for 4 plants which illustrate the results 

 obtained. 



Plant R 12-11-59, no. 63. A plant feebly self-compatible from the 

 first day of blooming and judged to be 4 7o self-compatible. Bloomed 

 from July 11 to Aug. 21. The dates of pollinations and number of seed 

 per head were -.—July 12th, 0, 0, 0, 2, 4, 7 ; 16th, 0, 0, 0, 0, 0, 0, 0, 0, 0, 

 0, 0, 0, 0, 7, 8 ; 22nd, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 ; 2Sth, 0, 0, 0, 0, 9 ; 29th, 

 0, 0, 0, 0, 1 ; Aug. 2nd, 0, 0, ; 15th, 0, 0, 0, 0, 2, 2. From Aug. 5th 

 until the 21st few and scattered flower heads were produced and the 

 branches were dying and becoming dry and brittle. The heads tagged 

 for selfings were well distributed over the plant. 



Plant B 12-11-59, no. 2. Bloomed from July 1 until Aug. 20. 

 Record as follows -.—July 2nd, 0, 5, 11 ; 5th, 0, 3, 6 ; 8th, 0, 0, 0, 0, 0, 1, 3, 8 ; 

 12th, 0, 0, 0, 0, 0, 2, 4, 9 ; 16th, 0, 0, 0, 0, 0, 0, 0, 0, ; Aug. 8th, 0, 0, 0, 0, ; 

 12th, 0, 0, 0, 0, 1. These results seem to indicate that the plant was 

 feebly self-compatible at first but less so later. 



Plant R 12-11-59, no. 6. Bloomed from July 12 until Aug. 23. 

 A completely self-incompatible plant. Dates and number of heads 

 given -.—July 12th, 2 ; 15th, 15 ; 18th, 5 ; 22nd, 12 ; 25th, 6 ; 29th, 5 ; 

 Aug. 2nd, 6 ; 5th, 5 ; 7th, 10 ; 8th, 7 ; 9th, 4 ; 17th, 2 ; 19th, 1. All heads 

 failed completely as shown in fig. 1 of Plate III. There were no 

 partially formed seeds. 



Plant R 12-ll-If.9, no. 79. A plant completely self-incompatible. 

 All the pollinations here recorded were made by hand. Plant bloomed 

 from June 21 until Aug. 13. Dates and number of heads selfed are as 

 follows -.—June 21st, 2 ; 2J,thi 1 ; 26th, 5 ; 28th, 8 ; July 2nd, 10 ; 5th, 5 ; 

 10th, 6 ; 21st, 5 ; 23rd, 4 ; 26th, 3 ; Aug. Jfth, 8 ; 6th, 3 ; 8th, 1 ; 9th, 1 ; 

 12th, 1. 



