THE ABORTION OF OVULES 357 



of the ovules and of the young seeds be principally restricted 

 to the centre of each compartment, the fruit-walls collapse in 

 the middle and we get a fiddle-shaped fruit, as shown in the 

 figure. 



Then, again, if the failure of the ovules and young seeds 

 takes place mainly in one loculus, whilst the seeds in the other 

 two for the most part develop normally, the mature fruit then 

 assumes a curved or arcuate shape, the concavity corresponding 

 to the compartment in which the failures are situated. Some- 

 times in arcuate fruits two loculi or compartments correspond 

 to the concave side ; and then it will be found that seeds are 

 lackins: in the centre of each of the two loculi concerned. If 

 the third compartment had been similarly aflTected, a fiddle- 

 shaped fruit would have been produced. However, the 

 essential feature of the arcuate type of fruit is a full set of 

 seeds on the convex side, associated with extensive abortion 

 or failure of the ovules and very young seeds on the concave 

 side. Such are some of the commoner types of deformation 

 of these capsules ; but lesser irregularities arising from the 

 same cause are numerous. 



Irregular forms of the capsule, such as are frequent with 

 Iris Pseudacorus^ are not so common with Iris fcvtidissima. The Iris foetid- 

 fruits of the last named are useful in illustrating the fact that ^"**"^* 

 there is always a variation in the original number of ovules 

 in each compartment of capsules of this type. The variation 

 is not large, but it is sufficient to indicate a possible initial 

 disturbing influence that would afi^ect the symmetry of the 

 plurilocular capsule. There are here appended the results 

 obtained from four flowers of Iris fatidissima for the three 

 loculi. 



A : 18 + 18 + 20 ovules 



B : 20 4- 22 + 22 „ 



C : 17 + 17 + 21 „ 



D : 16 -h 16 + 18 „ 



Respecting the distribution of aborted ovules in the several 

 compartments of a plurilocular capsule, I obtained the following 



