1922] Taylor — Biology of Wasps of Genus Ancistrocerus 55 
In the species of Ancistrocerus which have come to my 
notice, the wasps which have developed from the innermost 
cells of a nest have been invariably females. These inner cells 
are always of greater capacity and more bountifully provisioned 
than the smaller, outer cells, which are destined to give forth 
males 6 . In a very painstaking study Fabre (1884) found a 
similar distribution of the sexes in the nests of certain solitary 
wasps and bees. Later Verhoeff (1892a, 1892b) made like ob- 
servations and gave the name proterothesie to this phenomenon. 
Bordage (1912) and Roubaud (1916) have found it also in 
solitary wasps of the Malagasy and Ethiopian regions. This dis- 
position of the males and females is supposed by authors to permit 
the males on emerging to fly about and thus come in contact 
with females from other nests, achieving cross-fertilization. In 
one of the nests which I had in confinement, however, (nest no. 2) 
one of the first two emerging males constantly sat at the entrance 
of the nest from which it had just escaped, apparently waiting 
for a female. The next wasp to emerge was another male; the 
new arrival was met with palpations of the antennae similar to 
those which precede copulation. In nature, however, this might 
not have occured. 
In- confinement copulation was witnessed. The female ap- 
parently copulates but once, as the one observed repeatedly 
rejected males after having been fecundated. The males, on the 
other hand, are apparently able to fertilize more than one female, 
since they make repeated attempts after their first mating. 
The tables given above show several instances of longevity 
among individuals of this species, both in males and in the single 
female, one individual of each sex living longer than three months. 
Whether the period of life would be as long under normal con- 
ditions of subsistence and expenditure of energy is perhaps 
questionable, but it seems highly probable that a single female 
lives sufficiently long to construct several nests of the type 
described in this paper. 
6 This difference in size is evidently the general rule. Aberrations have been noticed and 
one of these is shown in figure 2, where cell No. 2 is larger than No. 1. This condition seems to 
be exceptional. 
