62 
Psyche 
[March 
formed a natural roof over the nest, but the base of the spathe had 
so rotted that the weight of the nest caused it to break (Fig. 4). 
The nest had lain on the ground for more than a week, but the adults 
had not abandoned it. The fall had torn the nest away from the 
spathe, but the combs lay stacked on top of one another in the 
normal position relative to one another, so the nest could be roughly 
reconstructed (Fig. 5). 
The nest was constructed of fine-textured carton of a uniform 
tan color. The cells averaged 5.9 mm in diameter (measured be- 
tween midpoints of opposite walls) and opened on the convex sides 
of the combs. The silken caps of the pupal cocoons were slightly 
domed, and were not covered with bits of carton. The bottoms of 
the cells were convex, giving the backs of the combs a mammillated 
surface. 
There were twelve combs, each hanging vertically from an edge 
by several pillars, and not surrounded by an envelope. The combs 
were constructed as concentric semi-cylinders around a vertical axis 
at one side of the spathe. Each comb was connected to adjacent 
combs by many pillars (Fig. 6). The comb nearest the central axis 
was the smallest and apparently was the first to have been built. 
Between combs 5 and 8 were three combs. Two of them, labelled 
6 and 7, were at the proximal end of the nest (end nearest the base 
of the spathe; see Fig. 5). The third, called 7a, filled up most of 
the remaining space at the distal end of the nest. A vertical dis- 
continuity between the right and left sides of combs 4 and 5 (Fig. 8) 
suggests that these two combs were initially composed of separate 
right and left portions which were fused as they were enlarged 
toward one another. A similar situation seemed to have occurred 
in the case of combs 6, 7 and 7a, except that 7a and 7 (or 6) were 
never fused. The size and brood contents of each comb are given 
in Table I. 
The presence of a meconium in a cell indicated that the cell had 
produced an adult. No attempt was made to determine the presence 
of more than one meconium in a used cell. Within a given comb 
the brood decreased in age from the center outwards. Comb 8 
Fig. 6. Combs 4-7 of the S. testacea nest showing how they are inter- 
connected by numerous pillars. About 1/2 natural size. 
Fig. 7. Comb 3 of the S. testacea nest in position on the spathe, combs 
4-11 removed. The white caps of the pupal cocoons cover most of the 
central cells. 
In Figs. 7-9 the combs are shown in an upside down position; that is, 
the edge from which each comb is suspended from the spathe is at the 
bottom of the figure. The proximal end of each comb is to the right. 
