456 
DISCURSIVE NOTES ON THE 
ever, is exceptional among Eossors. It is matched among 
bees, many genera of which make their nests in convenient 
empty receptacles such as snail-shells, hollow stems, &c. 
Let us spend a few minutes over Sceliphron spirifex ( vide 
Frontispiece, Fig. 8 , Sceliphron spirijex, L., and photo 5) — a 
very familiar species in houses— the long-legged, black and 
canary-yellow ‘ mud-wasp,’ so detested by housewives because 
of the mud nests it makes behind pictures, inside the backs 
of books, &c., wherever it finds a secluded nook that suits its 
fancy. Its habits are much like those of the true ‘ mud- 
wasps ’ — black insects with red, or orange-tipped, abdomen 
(vide Frontispiece, Fig. 4, Synagris negusi) that have the 
folded wings of the true wasps, but lead solitary lives. 
These, however, always make a single large nest, com- 
posed of many cells under a common outer shell, stuffed with 
caterpillars, the united mass being as big as one’s fist. Sceli- 
phron builds a number of separate cells, each about an inch 
long, of internal calibre the diameter of a lead pencil. Often 
she puts one against the other, but not by any means of 
necessity. The home of each larva is complete in itself, and 
a wonderful bit of work, too ! The little banda, in which 
I now write, is noisy with these busy workers from 7 a.m. to 
nearly sunset. First the sonorous hum, which has caused 
the Baganda to call Sceliphron * Bumbuzi ’ ; then the curious 
high-pitched buzz, rising and falling as with deft manoeuvres 
one spreads out the pellet of moist earth which she has brought, 
making it adhesive with saliva, so that it binds to the last 
layer. The cell is begun at one end and built in sections, each 
pellet that is brought making a new section, the bore being 
kept very uniform. Immediately one pellet has been used, 
off she goes, to return with another in a very few minutes. 
The pellet is about the size of a sweet-pea seed, and is held in 
her mandibles. 
While writing one morning, I timed the journeys of a single 
worker which was commencing a nest where I could watch 
its arrivals and departures. The following times represent 
her arrivals with a fresh pellet : 8.45, 8.48, 8.50J, 8.57J, 9.1, 
9.6, 9.8J, 9.121, 9.i 7j 9.231, 9 97, 9.30, 9.381, 9.361, 9.391, 
9.411, 9.441 9.47. 
