56 
Psyche 
[April 
Ancistrocerus capra de Saussure. 
The habits of this wasp have been recorded briefly by the 
Peckhams (1900), who describe three successive nests cons- 
tructed by this species in the mouthpiece of a tin horn. Their 
observations differ from mine in that they found the duration of 
the egg stage to be four days instead of two. These authors point 
out the similarity of the habits of this species to those of the 
European A. nidulator de Saussure, observed by Fabre (1891). 
The Raus (1918) have published observations on a nest made by 
capra in a woody elder twig, in which the innermost cell was of 
much greater capacity than the seven (one empty) additional 
cells, but no mention is made of the sex of the wasps reared from 
the nest. Observations of Rev. T. W. Fyles, reported b}^ Ash- 
mead (1894), show that this species provisions its nest with larvae 
of the larch saw-fly ( Lygceonematus erichsonii Iiartg.) Unfor- 
tunately I did not preserve any of the larvae used by capra, but I 
am almost certain that in this case they were lepidopterous 
rather than of saw-flies. It seems probable that species of An- 
cistrocerus do not limit themselves to a particular kind of cater- 
pillar, but avail themselves of whatever desirable food may be 
abundant. 
Nest No. 6. At 3:30 P. M. on June 20, I observed a large 
Ancistrocerus apparently just selecting her nesting place. She 
made repeated entrances, coming out each time and flying off for 
a short distance, apparently carrying nothing. She was possibly 
making a long distance locality study. Soon she began to bring 
in mud, out of which she constructed a basal partition at about 
7 mm. from the interior end of the tube. During the cons- 
truction of this partition I took many liberties with the nest, 
removing the glass tube during the wasp’s absence and sometimes 
failing to get it replaced before she returned. She seemed little 
disturbed. Once, as she hovered before the window sill where 
her nest should have been I slowly placed it in front of her and 
she entered as though nothing had happened. Perhaps as a 
result of this interference, she abandoned her first partition and 
started another about 5 mm. from the first. When this was 
