Tens. 



358 STUDIES IN SEEDS AND FRUITS 



Sdlla data for Scilla nutans. Here each of the three loculi of the 



ovary contain from ten to twelve ovules, and each of the three 

 compartments of the fruit on the average seven or eight seeds. 

 As a rule early failure of the ovules and of the young seeds 

 takes place with fair uniformity in the different compartments. 

 Fruits displaying such variations in the number of seeds in each 

 of the loculi as five, eight, seven, were frequent ; whilst those 

 where the divergence was greater, such as. three, eight, six, 

 were infrequent. Out of a large number of fruits examined, 

 none ever displayed a complete failure of the seeds in one 

 compartment. 



Primula I will now take the capsules of Primula veris, in which 



most of the abortions of ovules and of the failures of young 

 seeds take place around the base of the placental column. A 

 typical ovary contains on the average about ninety white ovules. 

 Of these all at first respond to the stimulus of the pollen, 

 but only about sixty mature as seeds. Of the remaining ovules 

 about twenty-two abort early when still uncoloured, whilst the 

 rest (eight) turn green and advance a little in their growth before 

 they too fail. Thus in Primula capsules we have a colour- 

 indication which enables us to distinguish between the early 

 failures of the ovules and the later failures of the young 

 seeds, the first white, the second green like the growing seeds. 



Allium In Allium ursinum we have a three-celled ovary, each cell 



containing two ovules. Of the six ovules only three on the 

 average mature as seeds, and often only two or even only one. 

 In all cases the ovules that abort early and the seeds that soon 

 fail combine with the mature seeds to make up the original 

 "complement of six ovules in the flower. The ultimate form 

 of the fruit is, as might be expected, very variable, and 

 irregularities almost appear to be the rule. Regular fruits 

 have a seed in each cell ; but it is not uncommon to find 

 two seeds in one cell, one seed in another, and none in the 

 third, and then the shape is very irregular. However, all 

 the ovules begin to enlarge after the fertilising process and 

 at the same time all the cells enlarge as well ; but when the 



ursmum. 



