A. St Clair Caporn 255 



Between the plots 1 ft. 3 in. paths were left to facilitate examination 

 of the growing rows from both ends. The same object was also attained 

 by shortening the rows a trifle, so as to make them contain 24 grains 

 instead of the usual 28. 



A panicle was held to be fully mature when the last trace of green- 

 ness had vanished from the tips of the paleae. Finding the ripe heads 

 by this method is not so laborious as might at first be imagined. For 

 the colour of the glumes is more or less an indication of the ripeness of 

 the grains they enclose. To pick out the ripe ones, therefore, it is 

 only necessary to peep in between the glumes at the base of the 

 yellowest panicles. This system of gauging ripeness was preferred to 

 any based on the times at which the panicles emerged from their 

 sheaths, because the rate of ripening of any two panicles leafing at 

 the same time appears to vary a good deal. 



At every daily inspection the heads cut out were given separate 

 labels bearing the number of the row and the date. After the whole 

 crop had been thus gradually harvested, the ripening period for each 

 row was obtained and recorded. The results are collected together in 

 Table I. 



The Mesdag row started ripening on Aug. 10th. It had finished 

 on Aug. 24th. Over 70 °/„ of the plants came to maturity within the 

 first five days. Ten days elapsed before the first panicle in the Hope- 

 town row could be cut. Here again the period was 15 days, but 

 the sequence of the ripenings was much more regular. (See end of 

 Table.) 



On examining the table it will be noticed that no row is as late as 

 the late parent, and none capable even of reasonable approximation 

 to it. Nor is there any exactly as early as Mesdag, although two, 

 Nos. 17 and 97, extend only two and three days respectively beyond 

 the Mesdag period. If, however, as is likely, a certain amount of 

 latitude must be given, then these two rows are to be reckoned 

 equivalent to parental Mesdag in earliness. Two out of 106 may possibly 

 indicate a 1 : 63 ratio. 



Another survey of the table reveals the fact that there are 24 rows 

 whose ripening period, starting early, extends over the gap between 

 the parental times and finishes on the first day of the Hopetown harvest 

 (Sept. 4th). The reverse condition, in which ripening starts immediately 

 after the last Mesdag, is not found at all. The number 24, however, is 

 possibly significant ; for it offers a very close agreement with 265, which 

 is the expectation on a 1 : 3 basis. 



