C. T. PRIME 



185 



significant differences in 1935 and 1939. Further in 1935, the number of ovules in 

 A. maculatum was greater than expectation, while in 1939 the reverse was the case. 



The average seed output (average number of ripe seeds per fruit X average number 

 of fruits per spike) of the two forms is shown in Table 7. 



Table 7 



The average seed output of A. maculatum and var. immaculatum 





Average number fruits 



Average number seeds 



Seed 





per spike 



per fruit 



output 



A. maculatum 



26-63 ± -41 (a = 6-74) 



1-36 ± -036 {a - 1-17) 



36-21 



var. immaculatum 



27-98 ± -34 (a - 6-77) 



1-18 ± -021 (a = 1-09) 



33-01 



Thus the significant differences observed between the seed production of the two 

 forms do not account for the preponderance of the var. immaculatum and it is unlikely 

 that they have any biological significance. A difference in the rate of vegetative repro- 

 duction would account for the greater frequency of var. immaculatum but individual 

 corms vary so greatly in this respect that it has not been possible to demonstrate an 

 overall significant difference. Many other factors, besides the reproductive, could operate 

 to produce the observed distribution. 



REFERENCES 



ARMITAGE, E., 1921, Some observations on Arum maculatum. Lanes. & Chesh. Nat., 13, 121. 



BROMFIELD, W. A., 1856, Flora Vectensis. London. 



CHRISTY, M., 1914, The coiling of Arum spathes. /. Bot., 52, 258. 



COLGAN, N., 1911, On the inheritance of pitted leaf markings in Arum maculatum and floral variation 



in the species. Irish Nat., 20, 210. 

 HOCK, F., 1934, in Kirchner, Loew & Schroeter, Lebensgeschichte der Bliitenpflanzen Mitteleuropas, 1 

 (3), 1-80. 



PETHYBRIDGE, G. H., 1904, The leaf spots of Arum maculatum. Irish Nat., 12, 145. 



PRIME, C. T., 1951, The Biology of the British species of Arum. University of London Ph.D. thesis. 



SALISBURY. E. J., 1942, The reproductive capacity of plants. London. 



SOWTER, F. A., 1949, Arum maculatum, in Biol. Fl. Brit. Is.^ /. Ecol, 37, 207. 



