COMPARATIVE VARIABILITY IN THE HONEY BEE. 33 



could be considered as in any sense mutations since there are in 

 all cases varying degrees of abnormality indicating a gradual 

 variation in the directions indicated. 



No attempt has been made to correlate definitely these ab- 

 normalities with any lengths of the neighboring veins, but in a 

 general way it can be said that the largest wings of each sex are 

 the most abnormal, and this fact explains to some extent why 

 the drone wings are so much more abnormal than those of the 

 workers. From this it would appear that the cause of these 

 abnormalities was the need of extra strengthening of the cells 

 as they became larger, and that the irregularities are the result 

 of extra growth energy, which has a chance to show itself when 

 room is allowed for its manifestation. 



SOME EXPLANATIONS OF THESE RESULTS. 



With theseYacts before us it seems desirable to find, if possible, 

 some explanations for these peculiar results. As stated in the 

 introduction the theory of germinal variation would lead one to 

 believe that the parthenogenetic individuals of the bee would 

 show less variation than those from fertilized eggs and if there 

 were no complicating factors it may be supposed that this would 

 be true, but there are certain factors which modify this result so 

 that the ratio of variation is exactly reversed. 



In the first place that kind of parthenogenesis in which males 

 only are produced (arrenotoky), is not such a specialized form of 

 agamic reproduction as are those kinds of parthenogenesis in 

 which females or both males and females are produced. When 

 females only result from parthenogenetic eggs (thelytoky], a 

 crossing of two lines of heredity seldom occurs and amphimixis 

 can bring about little variation. In the case of the Aphids and 

 Daphnids we have a similar condition except that once in a year 

 or once in some life cycle males also are produced parthenoge- 

 netically and then there is an opportunity for the blending of hered- 

 itary traits through fertilization. To this last form of partheno- 

 genesis the name amphoterotoky is applied. It is thus seen that 

 in arrenotoky this mixing of hereditary traits is not dispensed 

 with to such an extent as in the cases of thelytoky and ampho- 

 terotoky. On the other hand, the production of females par- 



