Field Studies of the Non-Nocial Wasps 345 
It is fascinating indeed to think of our own little hand- 
ful of P. mellipes as displaying perhaps a more advanced 
point in their evolution than other members of even their 
own species, and exhibiting a type of behavior more ad- 
vanced than that of any other member of the genus whose 
habits have been recorded. In this connection we must 
not overlook one Philippine species, P. nyemitawa, whose 
unique habits are recorded by Williams. This wasp 
pastes its nest, consisting of two or three cells, on tree 
trunks, in rather exposed situations, but the structure 
seems proof against wind and weather, being varnished 
over with a tree gum. The cells are made of an earth- 
like substance such as is used by the termites for their 
Coverways. ‘‘The wasps first sip up some water from 
Some convenient hollow or edge of stream, and the ball 
of earth subsequently gathered is worked around in her 
mouth until it assumes the right consistency, when it is 
plastered on the building site with the dorsal tip of the 
abdomen. * * * Before the cell group of two or three 
cells is completed a partial coat of varnish may be put 
on. The cells finished are more closely united with mud. 
x When Pseudagenia is through with the mud she 
turns her attention to a tree gum which she works over 
in her mouth-parts and spreads on precisely as she did 
the mud. Then without intermission she brings in an- 
other final coating or rather patching material—a pale 
8tay lichen—which she works up in her mouth into a 
Sort of viscid paste also applied like mud and varnish, 
but the nest is blotched rather than completely covered.” 
There is a small outbuilding at Wickes which harbored 
a number of old mud nests of Sceliphron caementarium 
in addition to a few nests of Polistes pallipes. For two 
years, 1917 and 1918 the inhabitants therein were ob- 
jects of study. The ecological succession of life, even in 
