388 ANNUAI^ REPORT SMITHSONIAN INSTITUTION, 1919. 
and long vigils with electric light and lanterns, we were never lucky 
enough to witness an emergence. Other watchers at Falls Church, 
Virginia, report no better success. Do the insects leisurely open their 
doors some time in advance of their actual need and wait below till 
the proper hour, or do the}^ break through the thin caps of earth and 
emerge at once? Digging up many open chambers revealed a living 
pupa in only one. Another issued from one of several dozen holes 
filled with liquid plaster for obtaining casts. Add to this the fact 
that great numbers of fresh holes are to be seen every morning dur- 
ing the emergence season, and the evidence would appear to indicate 
that the insects open their doors in the evening and come out at once. 
Onl}^ one chnmber was found in the daytime partly opened. 
If the insects are elusive and wary of being spied upon as they 
make their debut into the upper world, a witness of their subsequent 
behavior does not embarrass them at all. However, events are 
imminent, there is no time to waste. The crawling insects head for 
any upright object within their range of vision — a tree is the ideal 
goal if it can be attained, and since the creatures were born in trees 
there is likely to be one near by. Yet it frequently happens that 
trees in which many were hatched have been since cut down, in 
which case the returning pilgrims must make a longer journey per- 
haps than they anticipated. But the transformation can not be 
delayed; if a tree is not accessible, a bush or a weed, a post, a tele- 
graph pole, or a blade of grass will do. On the trees some get only 
so far as the trunk, others attain the branches, but the mob gets out 
upon the leaves. Though thousands emerge almost simultaneously, 
they have not all been timed alike. Some have but a few minutes to 
spare, others can travel about for an hour or so before anj^thing 
happens. Several that I buried in the ground hoping to watch them 
emerge, transformed in their graves. 
The external phase of transformation, more strictly the shedding 
of the pupal skin, has been many times observed. It is nothing more 
than what all insects do. But the cicada is notorious because it does 
the thing in such a spectacular way, almost courting publicity where 
most insects are shy and retiring. As a consequence the cicada is 
famous; the others are known only to prying entomologists. 
Let us suppose now that our crawling pupa has reached a place 
that suits it, say on the trunk of a tree, or better still on a piece of 
branch provided for it in a lighted room where its doings can be 
more clearly observed. Though the insects choose the evenings for 
emergence, they are not bashful at all about changing their clothes 
in the glare of artificial light. The progress of this performance is 
illustrated by figure 3. The first drawing shows the pupa still creep- 
ing upward; but in the next (^) it has come to rest and is cleaning 
'^ 
