ches, zealously prosecuted during a
number of winters, procured me only series containing a small number of
cocoons, four or five at most, often one alone. And, what is quite as
serious, nearly all these series are spoilt by parasites and allow me to
draw no well-founded deductions.

I remembered finding, at rare intervals, nests of both the Anthidium and
the Megachile in the hollows of cut reeds. I thereupon installed
some hives of a new kind on the sunniest walls of my enclosure. They
consisted of stumps of the great reed of the south, open at one end,
closed at the other by the natural knot and gathered into a sort
of enormous pan-pipe, such as Polyphemus might have employed. The
invitation was accepted: Osmiae, Anthidia and Megachiles came in
fairly large numbers, especially the first, to benefit by the queer
installation.

In this way I obtained some magnificent series of Anthidia and
Megachiles, running up to a dozen. There was a melancholy side to
this success. All my series, with not one exception, were ravaged by
parasites. Those of the Megachile (M. sericans, FONSCOL), who fashions
her goblets with robinia-, holm-, and terebinth-leaves, were inhabited
by Coelioxys octodentata (A Parasitic Bee.--Translator's Note.); those
of the Anthidium (A. florentinum, LATR.) were occupied by a Leucopsis.
Both kinds were swarming with a colony of pigmy parasites whose name I
have not yet been able to discover. In short, my pan-pipe hives, though
very useful to me from other points of view, taught me nothing about the
order of the sexes among the Leaf-cutters and the cotton-weavers.

I was more fortunate with three Osmiae (O. tricornis, LATR., O. cornuta,
LATR., and O. Latreillii, SPIN.), all of whom gave me splendid results,
with reed-stumps arranged either against the walls of my garden, as I
have just said, or near their customary abode, the huge nests of the
Mason-bee of the Sheds. One of them, the Three-horned Osmia, did
better still: as I have described, she built her nests in my study, as
plentifully as I could wish, using reeds, glass tubes and other retreats
of my selecting for her galleries.

We will consult this last, who has furnished me with documents beyond
my fondest hopes, and begin by asking her of how many eggs her average
laying consists. Of the whole heap of colonized tubes in my study, or
else out of doors, in the hurdle-reeds and the pan-pipe appliances, the
best-filled contains fifteen cells, with a