80 HEREDITARY CHARACTERS 



a genus of locusts. The triungulins of this beetle, unlike 

 that of Sitaris, run about actively, and hunt for the egg- 

 pods of the locust in cracks and holes in the ground. Did 

 the larvae of Sitaris act in this manner, they could not 

 arrive at the egg of the bee, for they are incapable of 

 living in the honey where it is deposited, until the first 

 metamorphosis has taken place. There appears to be no 

 way in which they could reach the egg except by slipping 

 from the body of the female Anthophora as she deposits it 

 upon the surface of the honey. 



The females of a genus of flies (Empis) live upon the 

 juices which they suck from the bodies of other insects. 

 The males of some species of this genus probably feed in a 

 like manner, but in no case are their habits so pronounced 

 in this direction as are those of the females, and in some 

 species the male is probably quite innocent. So voracious 

 are the females, that, did the males make amorous advances 

 without due precaution, it is quite probable their overtures 

 would end in a manner not at all conducive to the perpetua- 

 tion of the race. The instincts of the male Empis prompt 

 him to capture some insect, tempting to the female, and to 

 transfer it, generally living, to her clutches. While she is 

 occupied in dealing with the prey thus provided, the male 

 proceeds to the consummation of his courtship. 1 



Another instinct which is conceivable as having been 

 evolved by the selection of minute variations is the spin- 

 ning of a cocoon by a caterpillar. It seems inconceivable 

 that this can have been achieved by " a sudden leap." It 

 seems explicable only as the outcome of a long series of 

 minute progressive changes, but not of one or even several 

 large mutations. 



A mite, Antennophorus uhlmanni, is parasitic upon an 

 ant (Lasius). The mite is of such a size that it would 

 hamper the movements of the ant if it were attached on 



1 Hewlett, M., "Note on the Coupling of Empis Borealis," Entomologist's 

 Monthly Magazine, vol. xliii. p. 229, 1907; Hamm, A. H., "Observation on 

 Empis livida," Entomologist's Monthly Magazine, vol. xliv. p. 181, 1908. 



