Part I.] Beeson : Life-History of Diapus furtivus, Sampson. 11 
It may be mentioned that the male of Diapus impressus also posses¬ 
ses a group of secretory pores at the apex of each elytron, which is 
more extensive than that of Diapus furtivus. 
Construction of the Entrance Tunnel. 
The initial excavation of the entrance tunnel (Plate II, b) in the 
bole of the host tree seems to be undertaken independently by the 
male or the female beetle, as specimens of either sex may be found 
alone in partially constructed tunnels. When a pair of beetles is found 
in freshly commenced tunnels, it is usually the female who is innermost, 
and it is very probable that, shortly after a pair has associated, the 
excavation work is taken over entirely by the female. After the en¬ 
trance tunnel is completed the whole of the excavation of the gallery 
system is carried out by the female beetle. The long yellow brushes, 
borne on the front of the head of the female, are lost in the early stages 
of the excavational work, and no individuals found in tunnels, which 
have reached the sap-wood, still possess the brushes. Their function 
is obscure but is evidently only active from the time the beetle leaves 
her pupal cell, until she starts boring into the host tree. As the front 
of the head must be closely in contact with the terminal wall of the 
tunnel in order to bite through the fibres, the presence of a large tuft 
of bristles would be a hindrance. The possibility of the use of the 
frontal brushes, in connection with the transport of ambrosia fungus, 
is referred to on pages 14 and 15. 
Pairing. 
The act of pairing has not been observed ; it is equally possible 
that it takes place before flight in the old parent galleries, as after flight 
in the new entrance tunnel. One or two females captured out of a 
swarm were found on dissection to have ripe but unfertilized eggs in 
the ovaries. The female, however, lays eggs very shortly after boring 
into the tree, the first batch consisting of 5 to 15 eggs. The species 
is monogamous. 
The Gallery Pattern. (Plate II.) 
An examination of the literature on Platypodidae yields very scanty 
information with regard to the patterns of the gallery systems of vari¬ 
ous species. Of the genus Platypus some six or seven species from 
Europe, North and South America have been studied and their gallery 
patterns figured. One species of Periommatus from Africa has been 
L 11 ] 
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