244 



KELLOGG AND BELL 



Strictly blastogenic variation ; (d) that the variation in character 

 of venation, consisting of the addition of various spurs or parts 

 of veins (persistent remnants of phyletically lost veins (?) and, 

 more rarely, of interpolated new complete or nearl}^ complete 

 cells, is marked in the drones, which are males that are far- 

 theno genetically ^rodticed^ and is almost nil in the workers, 

 which are females (with ovaries in arrested development) that 

 are the offspring of hi-sextial -parentage; (c) that the variation 

 in lengths of certain parts of veins, subtended by cross veins or 

 by the forking of the veins themselves, is more than twice as 

 large as the variation in size of the wing (as indicated b}' the 

 length and breadth, or breadth alone) and is nearly the same 

 in both drones and workers ; {d) that the variation in number 

 of costal hooks of the hind wings is considerable and is about 

 the same in both drones and workers ; and (e) that the variation 

 in character of venation, length of vein-parts and number of 

 costal hooks in individuals fully developed, but taken from 

 cells at the time of their natural issuance, and thus not yet 

 exposed in free flying condition to the rigors of the struggle for 

 existence (/. e., the action of natural selection), is no greater 

 than, but is practically the same as in individuals which have 

 been exposed for a longer or shorter time to dangers of natural 

 enemies, and of the necessities of long and sustained flight (in 

 a word which have tested the worth of the wing structure as it 

 subserves the important function of flight), thus indicating that 

 these variations in wing characters do not have a life and death 

 selective value. The only variations in wing character in which 

 the individuals taken from cells (unexposed to the struggle for 

 existence) exceed free-flying individuals (exposed to the rigor 

 of selection among individuals) are those curious deformations, 

 to be looked on as malformations acquired during development 

 (due to cell pressure or accident) or if as blastogenic variations 

 then of the nature of sports or discontinuous variations of ex- 

 treme type. No free-flying form showed such a deformation 

 of venation and it is probable that no bee with such malformed 

 venation can successfully fly. 



Variations in the Number of Hooks and Character of Venation in 

 the Wings of Male Black Ants. — The ants are insects with com- 



