On the Species of the Genus Primula in Essex. 207
it to suck the nectar, or steal the pollen, while on the
wing.66
The old flower-stalks become dry, and remain on the plant
until the following year. On April 3rd last I found a great
number still standing from the previous spring in Peverill's
Wood. The capsules were as usual perfectly erect, although
the flowers are pendant; and they still held the majority of
55 [Prof. Hermann Muller, writing on P. elatior, says ('Fertilization of
Flowers,' Eng. Transl., 1883, p. 384) that pollen-collecting bees are only
able to secure their pollen from the short-styled flowers; they learn to
recognise the long-styled plants at a distance, and to avoid them; and thus
never perform cross-fertilization, but very often self-fertilization. He gives
the following list of twelve insect-visitors to the plant:—Aproa:: Bombus
hortorum, honey-sucking and collecting pollen, very abundant; B. sil-
varum, sucking normally; B. lapidarius, do.; B. confusus, do.; B.
terrestris, "makes a hole in the corolla-tube, a little above the calyx,
sometimes biting it with its mandibles, sometimes piercing it with its
maxilla?, and so reaching the honey with its tongue. (I have sometimes
seen this bee, before boring the flower, make several attempts to reach
the honey in the legitimate way—this observation is of interest, as proving
that the bee is not guided by instinct to the plant adapted for it, but that
it makes experiments, and gets its honey where and how it can)";
Osmia rufa, Apis mellifica, "I saw both these species thrust their tongues
into several flowers, and then abandon the plant" ; Anthophora pilipes,
sucking normally and collecting pollen, very abundant; Andrena gwynana,
collecting pollen on the short-styled form, abundant; "it holds the
anthers in the mouth of the flower with its fore feet, bites the pollen loose
with its mandibles, and sweeps it with the tarsal brushes of the mid-legs
into the collecting hairs of the hind legs. It visits the long-styled form
also, but flies away immediately ; not, however, without performing cross-
fertilization in the momentary visit. I have never seen a pollen-collecting
humble-bee alight on long-styled flowers; it seems to recognise them at
some distance, and to avoid them." Diptera: Bombylius discolor, sucking,
abundant; B. major, much less frequent, probably in most cases unable
to reach the honey. Coleoptera : Omalium florale, abundant, creeping
about in the flowers.
We abstract the above very interesting notes of Muller's at some length
for the purpose of calling the attention of botanists to the light the habits
of pollen-eating bees appear to throw upon the puzzling fact observed by
Mr. Christy, vit., that 1. are the most numerous, while s. are the most fertile
(see ante, pp. 162 and 167-8). Muller's observations seem to show that many
pollen-gathering bees habitually pass over the 1., but take abundance of
pollen from the s.; the result being that while the 1. would retain their