MOLTING. 



305 



caused to hatch earlier than they otherwise would have done. 

 The caterpillars were fed on the leaves of lettuce, and four 

 of them completed their transformations, — two males and 

 two females, — while three more died in pupating. The 

 males molted five times and the females six times. Wishing 

 to determine whether there would be any difference between 

 these caterpillars, hatched out of season, and those reared 

 under normal conditions, twelve newly hatched caterpillars 

 of the gypsy moth, each in a separate box, were given to 

 Miss Eose Davis, one of my assistants, early in May, 1893. 

 These were fed on apple leaves, and each molt carefully 

 noted. Of this lot, seven females molted five times, one 

 female molted four times and four males molted four times. 

 As these results differed so materially from those of Miss 

 Gordon, I took fifty-five newly hatched caterpillars in May, 

 1894, fed each on apple leaves, in a separate box, and care- 

 fully observed the molts myself. Fifty-two of these cater- 

 pillars completed their transformations, with the following 

 results : one female molted six times, twenty-nine females 

 molted five times and nine females molted four times ; seven 

 males molted five times and six males molted four times. 

 These results showed that in all probability no mistakes 

 were made by the other observers, and also that the process 

 of forcing the caterpillars makes no difference in the number 

 of molts, though the small number carried through by Miss 

 Gordon fails to make this point as conclusive as might be 

 desired. 



The time between the hatching of the eggs, which occurred 

 Feb. 3, 1893, and the first molt, and also between the 

 remaining molts, is as follows, according to Miss Gordon's 

 observations : — 



From the time of hatching till the first molt, 6 days. 



From the time of the first till the second molt, 7, 8 and 9 days. 



From the time of the second till the thhd molt, 6 and 7 days. 



From the time of the third till the fourth molt, 5, 6 and 7 days. 



From the time of the fourth till the fifth molt, 6, 7 and 8 days. 



From the time of the fifth till the sixth molt, 8 days. 



According to Miss Davis' observations, the time between 

 the hatching of the eggs, which occurred May 7 and 8, 1893, 



