THE CANADIAN ENTOMOLOGIST 175 



food to provide for the sustenance of the larva to which it gives birth ; 

 the two eggs in the present cases were deposited through some inadvert- 

 ence upon the part of the insect, and it does not seem wise to conclude 

 that a similar inadvertency had led to an accumulation of a double portion 

 • of food. If this double brood had been the result of mistake, it is not 

 possible that several mistakes of a similar kind would have occurred, since 

 it was my good fortune to meet with unoccupied cells that showed 

 evidence of being once occupied. 



If two eggs are deposited within the same cell, there must be collected 

 a double quantity of pollen and honey for the nourishment of the larvae. 

 The one which attained to full growth first would, no doubt, seek a clear 

 space in which to spin its covering, and this would be afforded by the 

 upper part of the tube or upper cell. The other, after having made a 

 sufficient space for this essential operation by the consumption of the 

 remaining food, would accomplish the task therein. 



Some cells, which it was my privilege to examine, exhibited faint 

 tracings of a partition-like arrangement between them. A portion of the 

 debris in the lower cell, to which reference has been previously made, may 

 have been due to the comminution of the leaves forming the separating 

 layers, through some cause or other. But this I am unable to substantiate. 

 If such should prove to be the case by future observations, there is 

 no doubt that there will be found to exist a separate accumulation of 

 pollen and honey in each cell. 



After a little reflection, there seems to be an offset to a portion of this 

 .argument. May it not be possible that after the two larvae had matured 

 into perfect insects, the more powerful one overcame the weaker, and that 

 the fragments of wings, legs, body segments, &zc., are the sad trophies of 

 such a conflict ? This point would be worthy of acceptance if every cell 

 which was examined had betrayed similar evidences. But it was not the 

 case. It only remains, then, to assume one of two opinions — either that 

 the two ova were deposited upon a double allowance of food, so that the 

 larv?e, when hatched, should find ample sustenance to reach maturity, and 

 subsequently had constructed their silken cocoons in their respective 

 positions, said positions being.determined upon by priority of growth ; 

 or, that a double cell was built, one on the top of the other, each properly 

 victualled and provided with an ovum. 



