No. 635] SHORTER ARTICLES AND DISCUSSION 547 



On May 25, the following experiment was made with these 

 creatures. Early in the evening before the time had arrived 

 when the creatures usually emerge in response to the low light 

 intensity prevailing after sundown, many were captured by in- 

 verting boxes, etc., over the burrows. Later in the evening many 

 more pupa? were captured as they were emerging from the 

 ground in response to the normal darkness following sundown. 

 Six were again placed on the damp earth beneath an empty, in- 

 verted flowerpot. Nine were placed as before in a full pot of 

 soil, over which a board was placed to prevent their escape. As- 

 controls, six were placed on the branches of a shrub and kept 

 under observation. One of the controls fell off and escaped. The 

 remaining five soon transformed in the normal manner. The 

 next morning, May 26, the pupae kept beneath the empty, in- 

 verted pot and those in the soil were examined. Of the six placed 

 on the bare soil beneath the empty, inverted pot, one had died 

 but the rest were active. None had transformed. All nine pupa? 

 placed in the pot containing soil were alive and crawling over 

 the top of the soil. Likewise none of these had transformed. On 

 the evening of May 26, three of these had died, but the remaining 

 six were as lively as ever. These were then given their freedom 

 and were allowed to crawl up into the branches of a small fringe 

 tree nearby. One fell off and was lost, but the remaining five 

 completed their transformations in the normal manner. Whether 

 this temporary inhibition of the act of transformation is voli- 

 tional or depends upon some factor of the soil environment act- 

 ing upon them is not definitely established by these experiments. 



After the pupa? ascend the shrubs and trees, rigidity sooner or 

 later takes place, and the adult begins its emergence from the 

 dorsal slit which opens in the pupal skin. It is not long until the 

 lax, soft-bodied creature is hanging head downward by the tip 

 of the abdomen. At this stage of its emergence, when it appears 

 as if the helpless, soft-bodied creature must fall to the ground 

 and perhaps suffer injury, it becomes very active, actually bend- 

 ing up to catch the exuvium or other near object with its legs, 

 just before the tip of the abdomen is released. Not all pupa? are 

 fortunate in their travels and transformations, however, for 

 many come tumbling to the ground from the trees while they are 

 making their way up the trunk and limbs. The almost helpless 

 transformed adults also sometimes fail to secure a foothold and 

 fall to the ground. It is interesting to note how quiekly pigmen- 



