J. W. H. Harrison 279 



(11) To replace this theory it is suggested that changed metabolism 

 favouring resistance to, or actually induced by, the use of food con- 

 taminated with metallic salts and other compounds affords a more 

 comprehensive explanation. 



(12) The influence of natural selection in establishing melanism, 

 when once developed, is not excluded, although the results from pro- 

 longed and exhaustive work on Polia chi showed that no selection, 

 favourable either to dark or to light forms, took place in the day time 

 from 5.30 a.m. to 7.30 p.m. 



(13) The inheritance of melanism in the genus Oporabia is not on 

 Mendelian lines. 



(14) The inheritance of the carpet band in the latifasciata form of 

 0. autumnata is on a sex-linked basis exactly the same as that of the 

 lacticolor aberration of Abraxas grossulariata. 



(15) In all probability the inheritance observed in the crosses 

 between 0. autumnata and 0. dilutata is likewise of the sex-linked 

 type; it may, nevertheless, be influenced by mitotic anomalies. 



(16) To the F^ generation and in the back crosses the hybrids 

 between 0. autumnata and 0. filigrammaria showed a perfect blend, no 

 traces of Mendelian segregation being determinable. 



(17) The evidence of the a utujunata- filigrammaria crosses afiforded 

 no support to the multiple factor theory of size inheritance. 



(18) In the Fg generation a delayed or pseudo-segregation is mani- 

 fested in which a portion of the brood still remain intermediate whilst 

 the remainder appeared in a uniform pseudo-mutational guise. This 

 strongly recalls the behaviour of Oenothera Lamarckiana and suggests 

 that the phenomena displayed by that plant are those of hybridity and 

 not of mutation. 



(19) A female from the intermediate portion of the F^ lot possessed 

 three antennae. 



(20) In the back crosses of the Fi filigrammaria x autumnata lots 

 one back cross with autumnata sufficed to restore the autumnata con- 

 dition ; on the contrary, it required the operation to be repeated twice 

 to bring the insect back to the filigrammaria facies. 



(21) In the autumnata-dilutata crosses very great disturbances 

 were observed : (1) the females in the cross between 0. autumnata ? 

 and 0. dilutata ^ emerged three months before the males and possessed 

 no ovaries ; (2) the reverse cross rarely produces females, never more 



