148 THE FERTILISATION OF FLOWERS. [PART In. 
75. Linum vsrratissiuuM, L.—This flower resembles the — 
preceding one in regard-to its honey, and to. the simultaneous — 
ripening and relative positions of anthers and stigmas ; hence also 4 
in the likelihood of cross-fertilisation in case of insect-visits, and — 
in the constancy of self-fertilisation if they fail. were 
Hildebrand has shown by direct experiment that self-fertilisation 
is efficient. ek 
The flowers are more conspicuous and therefore more, visited — 
by insects than those of L. cathartvcwm. Sprengel observed a 
humble-bee on them; I have noted :— ; a. | 
A. Hymenoptera—Apide : (1) Apis mellifica, L. 9, ab., s.; (2) Halictus 
cylindricus, F. 2, cp. B. Lepidoptera—Noctue : (3) Plusia gamma, L., s. 
See also No. 590, II. . 
Fic. 45.—Linum catharticum, L. 
1.—Young flower, from above ; the anthers are not yet in contact with the stigmas. a 
2.—Ditto, viewed obliquely from above. 
8.—A slightly older flower, from above; the five anthers are covered with pollen, and are in 
contact: with the stigmas. 
ne after removal of the calyx, to show the insertion of the petals and the position of the 
nectaries. 
5,—Essential organs removed from the flower, in the position of self-fertilisation. 
6.—Sepal from the inside, with a drop of honey. 
a, anther ; sf, stigma; n, nectary; a’, coherent filaments. 
The dimorphic species of Linum have been the subject of 
several important researches. 
Darwin, as early as 1863, recorded dimorphism in L. grandi- 
Joorum, Desf, L. perenne, L., and L. flavum, L., and made 
experiments on the two first. In Linum grandiflorum the short- 
styled flowers gave, on self-fertilisation, more seed than the long- 
styled, which remained almost barren. Both proved to be far 
