194 THE entomologist's record. 



with notes on the seasons in each locaHty, was doubtless of 

 great importance and aid in illustrating the paper. By this 

 means alone can the effects of the seasons and climate in 

 producing variation on any form be fully worked out. The 

 experiments of Mr. Merrifield and others have shown that 

 great variation can be produced by artificial methods, but the 

 results in all cases cannot be accepted as an exposition of the 

 natural causes of variation. They, however, will be the 

 means of suggesting other and better methods, and lead to 

 better results when studying the subject from a purely natural 

 aspect. 



The theory of the progressive development of bands on the 

 wings of lepidoptera caused by the union or coalescence of 

 lines in certain seasons and under certain conditions, is un- 

 questionably based on a line of reasoning that will ultimately 

 lead to the perfect elucidation of this form of variation, by it, 

 the genealogy of many so-called species and varieties will be 

 traced to this true source of origin. The variation of British 

 lepidoptera affords the best of all opportunities for the full 

 investigation of the subject. The many able and earnest 

 workers resident throughout the country, and the Continental 

 interchange of specimens, notes of experiments and discoveries, 

 will always enable British entomologists to lead the way in the 

 science of variation. The resolution recently adopted by some 

 of the London societies to devote certain evenings to special 

 groups or subjects is another step in the right direction towards 

 dispelling any doubts, and adding new facts to the subject 

 selected. 



With reference to Mr. Tutt's remarks on reversion and the 

 progressive development of Lepidoptera from dark to light 

 forms, or vice versa, I would remark that after much close 

 observation on the subject in New Zealand, I unhesitatingly 

 agree with Mr. Tutt in believing the former to be the right 

 view of the two. In all cases where dark or melanic forms 

 occur in our climate, they can readily be shown to be partial or 

 perfect instances of atavism produced in certain districts in- 

 variably more humid than the localities where the lighter forms 

 occur, and more typical of their ancestors formerly existing in 

 the ancient and more humid climate of the Islands. The New 

 Zealand climate has undergone considerable modification since 

 the advent of European settlement, and its effects are working 

 rapid and ruinous changes in the flora and fauna of the 

 country. The changes in the environment and economy of 



