Bramble-Bees and Others

sed, when they are in good enough repair. Early in the season the mothers quarrel fiercely over them; and, when one of the Bees has taken possession of the coveted dome, she drive

cell and flung away at a distance, atom by atom. The remnants of the cocoon are also thrown a

mother's ovaries are not exhausted. Finally, the dome receives, mainly over the apertures already plugged, a coat of plaster which makes the nest look like new. If she has not finished her laying, the mother goes in search of other old nests to complete it. Perh

but dried up or musty, because the egg has never developed. There are others containing a dead larva, reduced by time to a blackened, curled-up cylinder. There are some whence the perfect insect was never able to issue: the Chalicodoma wore herself out in trying to pierce the ceiling of her chamber; her strength failed her and she perished in the attempt. Others again and very many are occupied by ravagers, Leucopses (Cf. "The Mason-bees":

is unable to do so, or because she considers the removal unnecessary. Thus the base of the new cocoon is set in the bottom of the old cocoon. This double wrapper points very clearly to two generations, two separate years. I have even found as many as three cocoons fitting one int

most unequal, but always very small. It is saying much when there are enough to receive about half the laying. Four or five cells, sometimes two or even one: that is wha

rule were a constant one, we should be bound to find in the old domes at one time only females, at another only males, according as the laying was at its first or at its second stage. The simultaneous presence of the two sexes would then correspond with the transition period between one stage and the next and

n a glass tube 5 millimetres wide. (1.21 x.195 inches.-Translator's Note.) These cells contain males of the second or third generation and none but males. In the old femal

of recent production is here replaced by an irregular distribution, harmonizing with the number and holding-capacity of the chambers to be stocked. The Mason-bee has before her, let me suppose, only five v

d in a cell of the proper capacity. We can go further and admit that the mother alters the order of succession of the sexes at her pleasure, because her layings, between

arrangement, breaking up her laying into sections comprising both sexes just as required by the conditions imposed upon her. She therefore decides the sex of the egg at will, for, without this prerogative, sh

-bee of the Shrubs is very nearly a sphere. Of all shapes, the spherical shape is the strongest. Now these two nests require an exceptional power of resistance. W

e. Their elevation is the sine of the meridian arc starting from the plane of the pebble. Therefore, if they are to have any solidity, there must be large cells in the middle and small cells at the edges. And, as the work begins with t

s she to make use of the few vacant rooms, the large and the small alike, if the sex of the egg be already irrevocably fixed? She can only do so by abandoning the arrangement in two consecutive rows and accommodating her lay

rk is confined to repairs to the house, such as partitions and covers. There are plenty of these retreats; and the insect would always find first-class ones if it thought of going any distance to look for them. But the Osmia is a stay-at-home: she returns to her birth-place and clings to it with a patience extremely difficult to exhaust. It is here, in this little familiar co

engths and widths. In the long tubes, entire or almost entire layings, with a series of females followed by a series of males, were deposited. As I have already referred to this result, I will not discuss it again. The short tubes were sufficiently varied in length to lodge o

heir contents, only a part of the total laying, always began with female and ended with male cocoons. This order was invariable; what varied was

females followed by a male, which ends the series. From the 10th to the 17th of May, she colonizes a second tube, in which she lodges first three females and then three males. From the 17th to the 25th of May, a third tube, with three females and then two males. On the 26th of May, a fourth tube, which she abandons, probably because of its excessive width, after laying one female in it. Lastly, from the 26th to the 30th of May, a fifth tube,

a female and the upper by a male. There were a few exceptions. More discerning than I in her estimate of what was strictly necessary, bet

g, divides it into series as short as the room at her disposal demands; and each series begins with females and ends with males. This breaking up, on the one hand, into sections in all of which both sexes are represented and the division, on the

sten to the sweets of the almond-tree. In order to release themselves and emerge into the glad sunlight without disturbing the string of cocoons wherein their sisters are still sleeping, they must occupy the upper end of the

the nests of the Mason-bee of the Sheds, nests beloved by this particular Osmia. Old, disused hurdles supplied me with reeds inhabited

seen the Three-horned Osmia adopt that domicile. This may be due to the fact that these nests are isolated one by one in the fields; and the Osmia, who loves to feel herself surrounded by her k

has to perforate not only the plug, the lid built at the mouth of the cell, but also the thick plaster wherewith the dome is strengthened at the end of the work. The perforation results in a vestibule which giv

ous apartment in which one of the Osmia's females will find ample accommodation, for she is much smaller than the original occupant of the chamber, no matter the sex; but there is not room for two cocoons a

g slightly on the cell proper, and the residence is divided into two unequal storeys

rd storey is built, smaller than the second; and another male is lodged in this cramped corner. In th

bdivided into storeys when this is feasible. Economy of space is the chief consideration, since her stay-at-home tastes do not allow her to indulge in distant quests. She has to employ the site which chance places at her dis

nests of the Mason-bee of the Pebbles, of the cell properly so-called and of the exit-way which the perfect insect cut through the outer coating at the time of its deliverance. Their diameter is about seve

lower and the male the upper storey. True, in such cases economy of space is strained to the utmost, the apartments provided by the Mason-bee of the Shrubs

, which she would not do if the sexes were to follow upon each other in a settled order. For greater certainty, I numbered the cells of one nest as each of them was closed. On opening them later, I was able to see that the sexes were not subjected to a chrono

the banks inhabited by the Anthophora and sent to me from Carpentras by my dear friend and pupil M. Devillario. I examined them conscientiously in the quiet of my study. I found the Osmia's cocoons arranged in short series, in very irregular passages, the original

l shape and its coating of glazed stucco. In the latter case, the bottom cell, which once constituted, by itself, the chamber of the Anthophora, was always occupied by a female Osmia. Beyond it, in the na

s, of which the longest were series of four, included, with a wider diameter, first one or two females, then one or two males. It also happened, though rarely, that the series was reversed, that is to say, it b

n cell. The work of the whole swarm thus forms a stratum of cells that grows thicker from year to year. The corridors occupied by the Osmia are the holes which the Mason-bee dug in order t

whole laying into a continuous sequence of females and a continuous sequence of males, now breaks it up into short series in which both sexes are present. She adapts h

d nests which I have seen utilized by the Horned Osmia and the Three-horned Osmia at the same time. Less f

orizontal, polished with minute care and varnished with a sort of white glaze. It looks as if it had received a thin coat of whitewash. On the inner surface of this passage, in the thickness of the earthy bank, spacious oval niches have been excavated, communicating with the corridor by means of a narrow bottle-neck, which is closed, when the work is done, with a

es: to make her work more solid, she pours over the walls of the chamber a salivary liquid which not only whitens and varnishes but also penetrates to a depth of some millimetres into the sandy

at look like large grapes drawn out lengthwise. Each of these nodules is a cell, the entrance to which, carefully hidden, opens into the tube or passage. When she wishes to leave her cell, in the spring, the Anthophora destroys the mortar disk that clo

mmodious retreat for their families. The Horned Osmia and the Three-horned Osmia establish themselves there at th

of the Anthophora's cell; the upper storey includes the rest of the cell and a little of the bottle-neck that surmounts it. The two-roomed dwelling is closed, in the passage, by a shapeless, bulky mass of dried

n of sand 50 millimetres deep (1.95 inches.-Translator's Note.) and the top one by a column of 15 millimetres (.585 inch.-Translator's Note.). The holding-capacity of the one is therefore about three ti

ivided into three storeys. The bottom one, which is always the most spacious, contains a fem

es in it would be undue generosity to a sex that is entitled to but the smallest consideration. Besides, the two sexes must be represented in almost equal numbers. The Osmia decides upon one female, whose portion shall be the better room, the lower one, which is larger, better-protected and more nicely polished, and one male, whose portion shall be the

of cells, because the others were not free, being inhabited by the Anthophora. The cells in question were divided into three

named, the Common Snail, is the most often used, under the stone-heaps and in the crevices of old walls. Both Anthidia colonize only the second whorl of the spiral. The central part is too small and remains unoccupied. Even so with the front whorl, the largest,

es, the catkins of the conifers, small shells, dried excretions of Snails. Next come a partition of pure resin, a large cocoon in a roomy chamber, a second partition of pure resin and, lastly, a smaller cocoon in a narrow chamber. The inequality of the two cells is the necessary consequence of th

he two sexes were present together; the female, the smaller, occupied the front cell and the male, the bigger, the back cell. Other cells, which were smaller or too much obstructed at the back by the dried-up remains of the Mollusc, contained only one cell, occupied at one time by a female and at another by a male. A few, lastly, had

ned Osmia. The nest is established in a bit of reed 11 millimetres wide inside. (.429 inch-Translator's Note.) It comprises thirteen cells

the excessive width of the tunnel, which is too great for a series in single file, the Osmia appears to alter her mind. She therefore builds a partition perpendicular to the transversal partition which she has just constructed and thus divides the second storey into two rooms, a larger room,

The transversal partitions become more and more slanting and the work grows irregular, but always with a sprinkling of large cha

bottom is repeated. There is no longitudinal partition; and the spacious cell, covering the whole diameter of the cylinder, receives a female. The edifice end

ove the other. Here, the Bee is making use of a tube whose diameter is not suited to her work; she is constructing a complex and difficult edifice, which perhaps would not possess the necessary solidity if the ceilings were too broa