t^ii- CoLGAN. — Lcaf-blotcJiinvs in Arum maailatiun. 215 



stages of growth. For the greater part of the material used 

 in the inquiry, some 250 flowering or fruiting spikes, I am 

 indebted to the kindness of friends, above all to Mr. R. A. 

 Phillips, who collected for me in Galway, Tipperary, Cork, 

 Wexford, Kilkenny, and Queen's Co. Material from Derry 

 was sent me by Mr.W. E. Hart ; from Co. Down by the Rev. 

 Canon Lett ; from Wicklow and Kerry by Mr. W. F. Gunn ; 

 and from Co. Dublin by Mr. R. W. Scully. 



A total of 341 ovaries or immature fruits were dissected 

 in the month of May, 191 1, to ascertain the number of 

 ovules, and 661 mature fruits or berries were examined 

 between the 8th September and the 3rd October of the same 

 year. The result was to show that the ovules were much 

 more numerous than the ripe seeds and that the number of 

 both seeds and ovules was variable. The number of ovules 

 per ovary ranged from 2 to 8, the average being 4.8. Out of 

 the 341 ovaries examined 300 had from 4 to 6 ovules each, 

 none had less than 2, 23 had from 2 to 3, and 19 had from 

 7 to 8 ovules. In contrast with this distribution of the 

 ovules, the 661 ripe fruits examined gave an average of 1.4 

 seeds per fruit, the numbers ranging from i to 4. No less 

 than 443 of the fruits were one-seeded, 163 had 2 seeds, 

 45 had 3, and only 10 had four. 



In Ireland, then, less than one-third of the ovules of Arum 

 macidatum come to maturity, and, since 606 out of the 661 

 Irish Iruits examined had either i or 2 seeds, it is clear that 

 Ray's and Haller's accounts of the fruit are, for Ireland, 

 at all events, much nearer the truth than either Hooker's 

 or Babington's. 



This abortion of more than two-thirds of the ovules of 

 Arum niaculatum is, no doubt, mainly due to imperfect 

 pollination, as is the entire abortion of the fruit which not 

 infrequently takes place in this species. An examination of 

 22 fruiting spikes from the counties of Kilkenny and Wexford 

 made in September last showed that 70 out of a total of 

 595, or fully II 2 per cent, of the fruits, were completely 

 aborted. The number of aborted fruits and ovules is probably 

 in inverse ratio to the number of insect visitors to the spathe. 

 In the majority of the fully opened Irish spathes examined 



