110 THE FERTILISATION OF FLOWERS. [PART III. 
the two shorter stamens -has on either side of its base a honey- 
gland; each of the four honey-drops secreted by these lies in the 
space bounded by one of the shorter stamens, the adjacent long 
one, and the pistil. The anthers ripen along with the stigma, 
which their pollen-covered sides face; the taller anthers overtop 
the stigma and arch inwards, the shorter stand on a level 
with it, and curve slightly outwards. In default of insect- 
visits pollen regularly falls upon the stigma from the four long 
stamens. 
The flowers are very small, and for that reason insect-visits are 
scarce. The honey, however, seems to be particularly liked by cer- 
taininsects. On June 27, 1868, ona waste patch where S. officinale 
and Capsella bursa-pastoris were growing abundantly with several 
other plants, I noticed’ Pieris napi, L., and P. rape, L., flying about 
in great numbers, and sucking the flowers of this plant only. The 
point of the insect’s proboscis is thrust in between the stigma and 
the anthers. I also saw several specimens of Andrena dorsata, 
K. 9, in quest of pollen: they were probably as likely or more 
likely to effect self-fertilisation than cross-fertilisation. 
Visitors: A. Hymenoptera—Apide: (1) Andrena dorsata, K., ¢.p. and 
f.p. B. Lepidoptera—Rhopalocera: (2) ‘Pieris napi, L., s.; (3) P. rape 
L., s. See also 590, it. 
37. CAPSELLA BURSA-PASTORIS, D.C.—The only difference 
to be noted between this and the foregoing is that the long 
stamens stand on a level with the stigma, and effect self-fertilisa- 
tion regularly. Specimens which I kept in a room and protected 
from insects were fully productive. 
Visitors : Diptera—(a) Syrphide: (1) Eristalis nemorum, L., s. and fp. ; 
(2) Syrphus balteatus, Deg., do. ; (3) Syritta pipiens, L. ; (4) Ascia podagrica 
F., s. ;(5) Melithreptus scriptus, L. ; (6) M. teeniatus, Mgn. ; (7) M. pictus, Mgn., 
the last three s, and f.p. ; (b) Muscide : (8) Anthomyia,s. See also 590, U1. 
38. LepipiIumM sativuM, L.—The flowers are inconspicuous, 
but their strong scent is perceptible even to us several paces off. 
Owing doubtless to this, they are more abundantly visited than 
any other Crucifer which I have observed, partly for their honey, 
partly for their pollen. The honey is secreted by four green, 
fleshy glands, situated between the long and short stamens, and 
opposite to the petals; the two long stamens on each side face 
the broad surface of the silicula, and arise close together between 
the two lateral petals. The anthers dehisce introrsely, and the 
ee ee EN ene - eer 
