THE PINE INVESTIGATION. 



383 



The primary galleries. These are the galleries which branch 

 off from the main entrance or the nuptial chamber. 



Secondary galleries are excavated by the parent beetles, 

 and branch off from the main galleries. The larval mines are 

 sometimes called secondary galleries, but this term is, I think, 

 more properly applied to those excavated by the adults. 



The egg or brood galleries are the portion of the primary or 

 secondary galleries in which eggs are deposited, and from which 

 the larval mines, larval or pupal chambers, are extended, or in 

 the case of the ambrosia timber beetles, the portion of the gal- 

 leries in which the broods develop. 



Egg cavities.. These are cavities excavated by the parent 

 beetles in the sides of the brood gallers for the reception of 

 eggs. 



Larva and pupa chambers. These are short cavities or 

 chambers excavated by the larvae which extend at right angles 

 from the brood galleries of certain timber beetles. 



Larva mines. This term is applied to all mines excavated 



Fig. LV. -Galleries of Gnathotrichus materiarim in pine: a bark b saowood 

 c heart wood, 1 primary gallery ; 2, 3, 4, 5, e, and 7 secondary galleries ; 

 d, ,/, 9, h and i, brood galleries. 



