270 
Willis and Bur kill* — Blowers and 
the limit of Pteris ), Bombus terrestris (common to 1100 feet, 
and was seen at higher levels, though not visiting), B. lapi- 
darins (to 1800 feet), B. hortorum (do.), B. muscorum (freq. 
at 1100 feet), B. lapponicus (1800 feet on Calluna, the only 
record of this insect visiting flowers in Britain, that we 
possess), Melanostoma sc alar e (1100 feet), Sericomyia borealis 
(do.), Eristalis tenax (do.), L 7 icilia cornicina (to 1800 feet), 
and Scatophaga stercoraria (1100 feet). With the exception 
of Lucilia and the humble bees, none of these insects were 
noted above the limit of Pteris (1270 feet). So far, therefore, 
as these observations go, the flower-visiting insect fauna of 
our British hill-districts at alpine levels resembles rather that 
of northern Scandinavia and Arctic countries than that of 
corresponding zones in the mountains of central Europe. 
This side of the subject we hope to consider in detail in 
Part II. The flowers too seem on the whole to resemble 
those of Arctic regions in their great development both of 
autogamy and vegetative reproduction. 
6. Summary. 
The chief conclusions to be drawn from this work have 
been already given at the ends of the different sections, but 
we may add a few notes here. 
In all, 51 species of the British flora are treated of (in- 
cluding the three species of Medicago at Cambridge). Several 
figure more than once, viz. Jasione (Auch. Cardig.), Scabiosa 
(Auch. Scarb. Card.), Mentha (Auch. Scarb.), Calluna (Auch. 
Card.), Erica cinerea (do.), E. Tetralix (do.), Potentilla 
(do.). If each of these be counted separately the total 
amounts to 59. Three of these (Littorella, Ranunculus , 
Peplis ) have no insect visitors recorded. Adding up those 
of the remaining 56 (counting the plants named above as 
often as they occur), we get : — 
