322 Mr. 'Poultons farther experiments upon 



1888. 



The larvae hatched from eggs laid by moths from 

 Experiment II. (1887) will first be considered. The 

 puiDse of this experiment were kept in one receptacle, 

 and the moths emerged together, so it is impossible to 

 decide upon the number of moths which laid eggs ; but 

 the small batch obtained favours the conclusion that only 

 one did so. 



The experiments on this lot of larvae are given below 

 in a tabular form. 



Experiment I. 

 Dark Surroundings. 



July 1. — ^12 larvse introduced, still 

 quite young. 



Aug. 5. — 10 alive ; larvie were still 

 small and not very dark yet. 



Aug. 19. — 10 alive ; much darker 

 than II., but not so dark as might 

 be expected from the dark surround- 

 ings. Most were nearly mature. 



Sept. 3. — 9 alive ; 1 spun. The 

 results were not nearly so marked 

 as in II., but they were much darker 

 than these ; 3 of them were grey 

 rather than dark, the remainder 

 being darker, but only one very dark, 

 and this with some green on it. 



Sept. 12. — 1 more had spun and 

 7 left. 



Sept. 14. — Still 7 left, and not 

 very dark considering the condi- 

 tions; 3 were greyish and 1 of the 

 darkest was still greenish. Com- 

 l^ared witli the larv;c descended from 

 moths of Experiment III., 1887, 

 those in I. (of which only 5 could 

 now be compared safely, because the 

 others had undergone changes pre- 

 paratory to pupation) were rather 

 darker than these 7, but not much. 

 On the other hand, these 7 were 

 rather darker than the 4 II., and 

 much more so than the 5 IV. There 

 was only 1 III. left for the jJurposes 

 of comparison, and this seemed to 

 be about the same as these 7. 



Experiment II. 

 Green Surroundings. 



July 1.— 12 similar larva? intro- 

 duced. 



Aug. 5. — 8 alive ; still small. Com- 

 pared with I., these were decidedly 

 lighter and somewhat greener ; they 

 were not as yet very light and green. 



Aug. 19. — 8 alive ; these were 

 clearly greener and lighter, and good 

 examples of the effect of green sur- 

 roundmgs. 



Sept. 3. — 8 alive, 8 having spun 

 up ; 2 full-fed and green-grey in 

 colour : the results very characteris- 

 tic of green surroundings. 3 smaller 

 and not quite so green, but still 

 light varieties. 



Sept. 12. — 2 more had spun and 

 3 left. 



Sept. 14.— Still 3 left ; they were 

 very pale greenish grey, showing 

 distinctly the effects of the experi- 

 ment, far more than in I. Com- 

 pared with larval from moths of 

 Experiment III., 1887, these 8 were 

 certainly lighter than the 5 IV. now 

 left, much lighter than the 1 III. 

 and 4 II., and far more so than 

 the I. 



