THE INFLUENCE OF CHANGED EXTERNAL 

 CONDITIONS ON THE DEVELOPMENT 

 OF TWO SPECIES OF MOTHS 



PROFESSOR THOMAS H. MONTGOMERY, Jr. 



These experiments were carried out in the fall and 

 winter of 1908-09, and their results are not without in- 

 terest even though no marked changes in the insects 

 were effected. 



I. Attacus cecropia Linn. 

 Cocoons of this large Saturniid were collected in New 

 Jersey in December and January. The controls, kept 

 in their cocoons, were hung out-of-doors exposed to rain 

 and sun until the latter part of April, then placed in a 

 hatching cage in a room at out-of-doors temperature, 

 when they hatched in May. The pupa? to be experi- 

 mented upon were removed from the cocoons and kept 

 in horizontal positions unless otherwise specified. 



A. Experiments with Light 

 Direct Sunlight.— Four pupae, lot no. 86, of which only 

 one was healthy in appearance, were placed in direct 

 sunlight in a warm room (21° C.) on February. 5; one 

 of them hatched on February 10 and laid eggs, while the 

 other died. Evidently direct sunlight is not fatal to 

 them. 



Direct Sunlight behind a Heat Filter.— Twenty pupae, 

 lot no. 83, were laid horizontally on their dorsal sur- 

 faces with heads directed towards the sunlight, behind 

 a vertical flat glass jar containing a saturated aqueous 

 solution of alum, in a warm room (21° C). They were 

 thus placed on January 22, and all hatched in March 

 following. 



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