188 
JOURNAL OF THE PLYMOUTH INSTITUTION. 
To the Editor of the Plymouth Institution Journal. 
ON THE INSECTS THAT FREQUENT THE FLOWERS 
OF THE COMMON PRIMROSE. 
[Primula vulgaris. — Huds.) 
Foe two Springs past I have been endeavouring to gather facts 
bearing on the fertilization of the common Primrose, and to 
ascertain which species of our larger insects may, from being seen 
on its flowers, be reasonably considered to take part in eff'ecting 
this. My attention was first directed to the subject from my having 
read an article by Mr. Charles Darwin in the Journal of the Linnean 
Society (vol. x., Botany, pp. 437-454), wherein this distinguished 
writer, when speaking of the less obvious differences between the 
Cowslip and the Primrose, observes, "The Cowslip is habitually 
visited during the day by humble bees (viz., Bomhus rnuscorum and 
hortorum, and perhaps by other species), and at night by moths, as 
I have seen with the Cucullia. The Primrose is never visited (and 
I speak after many years' observation) by the larger humble bees, 
and only rarely by smaller kinds; hence its fertilization depends 
almost exclusively on moths." I made last year some remarks in 
the Journal of Botany (vol. viii., pp. 190-91) on these assertions 
of Mr. Darwin's, to the effect that in the neighbourhood of 
Plymouth we have a humble bee {Anthophora acervorum) that often 
visits the Primrose, and that I had caught individuals in the act of 
gathering from it. I added: "There is also a very small bee 
{Andrena Gynanna) that seems to get a vast quantity of pollen 
from Primroses ; for I have seen it on these flowers with the 
posterior tibae loaded with golden masses. The Brimstone Butterfly 
{Gonepteryx Rhamni) also visits them, as I have witnessed this 
Spring. We have another insect that seems to obtain most of its 
food from Primroses at this season of the year, visiting them 
perhaps more frequently than either of the bees or the butterfly : 
it is a dipterous one [Bomhylius medius). Repeatedly have I 
watched it inserting its long proboscis into the tube of the corolla, 
