Bramble-Bees and Others

suspect that it does, for each little heap of provisions is carefully proportioned to the needs at one time of a male and at another of a femal

ther one cocoon in a colony belongs to the same family as another. To compile a register of births is absolutely impossible here. Fortunately there are a few species in which we do not find this difficulty: these are the Bees who keep to one gallery and build their cells in storeys. A

an egg is laid on the surface of the food: that is the first-born of the family. At a height of some twelve millimetres (About half an inch.-Translator's Note.), a partition is fixed, formed of bramble saw-dust and of a green paste obtained by masticating particles of the leaves of some plant that has not yet bee

eries; the last-born is at the top, near the closed door. The others follow from bottom to top in the same order in which they foll

that object; besides, if we wait for the hatching-period before examining the brambles, it may happen that the order has been disturbed through some insects' having tried to make their escape as soon as possible after

n plug, an insuperable obstacle to the future insect. There is thus no fear that the contents of the cells may become mixed or transposed; and I am saved the trouble of keeping a laborious watch. Each insect can hatch at its own time, in my presence or not: I am sure of always finding it in its place, in its proper order, held

of cocoons varies greatly, sometimes falling as low as two, or even one. The mother has not deemed it advisable to confide her whole family to a single bramble-stump;

cocoon, or after spinning it. Lastly, there are parasites, such as the Unarmed Zonitis (Zonitis mutica, one of the Oil-beetles.-Translator's Note.) and the Spotted Sapyga (A Digger-wasp.-Translator's Note.), who inte

orty of this Osmia's nests, transferred their contents into glass tubes and made a careful summary of the sexes. I give some of my results. The figures start in their order from the bottom of the tunnel dug in the bramble and proceed upwards

11 12 13 14 15 F F M

, has or has not finished laying her eggs. The bramble-stump under consideration leaves a free space of nearly four inches above the continuous string of cocoons. Beyond it, at the actual orifice, is the terminal stopper, the thick plug which closes the entrance to the gallery. In this empty portion of

done in shifts, separated by intervals of rest. The space left empty in the channel would mean that one of these shifts was finished and not that there were no more eggs ripe for hatching. In answer to these very plaus

lastly we ascertain, as I have done ad nauseam in the case of the Three-horned Osmia, the time required for building and victualling a cell, it becomes obvious that the total laying must be kept within narrow bounds and t

rdering on fifteen represents the entire fami

e other complete s

2 13 F F M F M F M F F F

is taken as complete, for

plete, in view of the small number of cells and the

M M M F M F M M M F M F F M

death of the larva, the failure of the egg to hatch and other accidents-all that I can say in general is that the complete series begins with females and nearly always ends with males. The incomplete series can teach us nothing in this respect, for they are only fragments starting we know not whence; and it is

l now I have found only one of her nests, placed above a nest of O. detrita, in the same bramble. Here, instead of the lack of order in the distribution of the sexes which we find

les, beginning with the bottom of

: three females fir

t: five females fol

t: seven females fo

t: one female follo

en: six females fo

the series. Nos. 3, 4 and 6, on the other hand, look like the beginnings of layings: the females predominate and are at the head of the series. Even if these interpretations should be open to doubt, one result a

s a regular law with her kinswoman. The mother occupies herself at the start with the stronger sex, the more necessary, the better-gifted, the female sex, to which she devotes the first flush of her laying an

e previous witness has just shown us. This series, one of nine cocoons, com

e chase and pile their cells one after the other, in a row, showing the relative age of the cocoons. The brambles house several of these: Solen

his seems to me rather insanitary. To avoid the humidity, or for other reasons which escape me, the Solenius does not dig very far into her bramble-stump and consequently can stack but a small number of cells in it

ly": chapter 2.-Translator's Note.) I obtained only three series free from gaps: one of eight cocoons, comprising only females; one of six, likewise consisting wholly of females; lastly, one of eight, forme

roubling to be economical with a lodging which it has cost her nothing to acquire, she carelessly builds a few partitions at very unequal heights, stuffs three or four compartments with Spider

; the Anthidia (Cf. Chapters 9 and 10 of the present volume.-Translator's Note.), who weave their honey-wallets out of cotton-wool and arrange their cells one after the other in some cylindrical gallery. In most cases, the home is the produce of neither the one nor the other. A tunnel in the upright, earthy banks, the old work of some Anthophora, is the

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

, 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 wi

er 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 b

if the mother had any more eggs available, she would have lodged them in the room which she leaves unoccupied. This string of fifteen appears to be rare; it was the only one that I found. My attempts at indoor rearing, pursued during two years with glass tubes or reeds, taught me that the Three-horned Osmia is not much addicted to long series. As though to decrease the difficulties of the coming del

ecame rather higher, reaching fifteen. The most numerous laying performed under my eyes, not in a tube, but in a succession of Snail-shells, reached the figure of twenty-six. On the ot

front. The contents of these compartments are no less uneven between one portion and another of the string. Without any exception known to me, the large cells, those with which the series starts, have more abundant provisions than the straitened cells with which the series end

so sparingly. The first-born receive the benefit of her early enthusiasm: theirs is the well-spread table, theirs the spacious apartments. The w

the perfect insect, which will take place towards the end of summer. If impatience gets the better of us, we can open them at the end of July or in August. The insect is then in the nymphal stage; and it is easy, under this form, to distinguish the two sexes by the length of the antennae, which are larger in the

ee-horned Osmia consists of two distinct groups,

her nest in reeds, which she did with a zeal which I was far from expecting. All that I had to do was to lay some reed-stumps horizontally within her reach, in the immediate neighbourhood of her usual haunts

and widely-spaced partitions; in front, small cells, with scanty provisions and partitions close together. Also, the larger cells supplied me with big

the relative size of the two sexes, for the thing contained, the perfect insect, is evidently proportionate to the silken wrapper in which it is enclosed. These cocoon

i x a x (

e major axis and

of the cocoons of the Three-

's Note.), 2b = 7 mm. (.273 inch.-

's Note.), 2b = 5 mm. (.195 inch.

the two sexes. This ratio is somewhere between 2 to 1 and 3 to 1. The females therefore are two or three times larger

ves us the followin

's Note.), 2b = 9 mm. (.351 inch.-

r's Note.), 2b = 7 mm. (.273 inch

x 9 x 9 = 1215 and 12 x 7 x 7 = 5

certain the relative order of the two sexes, though not quite so precisely. One of these is the Mason-bee of the Walls. I need not descri

her site jealously, driving away any Mason who even looks as though she might alight on it. The inhab

osit the rest of her eggs. She is too thrifty of her time and of her mortar to involve herself in such expenditure except for grave reasons. Consequently, each nest, at least when it is new, when the Bee h

ls and we shall have the total list of the family. Their maximum number fluctuates round about fifteen

oups of cells, when finished, will have the oldest in the central portion and the more recent in the surrounding portion. Because of this juxtaposition of the cells, which serve partly as

their support with a few smart sideward taps of the hammer on the pebbles. At the base of the mortar dome the cells are wi

by this method during the last six or seven years. I will content myself with saying that the harvest of a single morning sometimes consisted of as m

al point, the same rule has been observed. A male cell is never surrounded on every side by female cells: either it occupies the edges of the nest, or else it adjoins, at least on some sides, other male cells, of which the last form part of the exterior of the clu

angle is a favourite site with the Mason, who thus finds greater stability for her edifice in the support given her by the double plane. These sites appear to me to be in great request with the Chalicodoma, considering the number of nests

ront of this first row come others. The female cells occupy the middle portion and the male the ends. Finally, the last row, closing in the remainder, contains only male cells. The progress of the work is very v

curs less often. The nest is then one of several storeys. The lower storeys, the older, contain only females; the upper, the more recent storey, contains none but males. It goes with

order of primogeniture. Theirs is the central and best-protected part of the clay fortress; the ou

ies of the two sorts of cells, I go to work as follows: I fill the empty cell with very fine sand and pour this sand back into a glass tube measuring 5 millimetres (.195 inch.-Translator's Note.

ngle. The female cells give me the following figures,

, 1.71, 1.67, 1.87, 1.87, 1.79,

1.75 inches.-Tr

e cells

1.36, 1.09, 1.17, 1.17, 1.21

1.21 inches.-Tr

portionate to its capacity, the above ratio must also be more or less the ratio of provisions and sizes between females and males. These f

opulous colonies; and it is impossible to follow the labours of any single Mason, whose cells, distributed here and there, ar

nging from a bough. Sometimes, this nest is the size of a large walnut and then appears to be the work of one alone; sometimes, it is the size of a man's fist, in which case I have no do

ilt by a single Bee. Here females are found in the centre of the group and males at the circumf

ies of males, the latter with less provisions and smaller cells. This distribution of the sexes agrees with what we have long known of the Hive-bee, who begins her laying with a long sequence of workers, or sterile females, and ends it with a long sequence of males. The analogy continues down

est of them fatally bound by this distribution of the sexes into two distinct groups, the male group following upon the female group,

e Horned Osmia and the Three-horned Osmia, who stack theirs methodically by separate sexes in the hollow of a reed? What the Bee of the brambles does cannot her kinswomen of the reeds do too? Nothing, so far as I know, can explain this differ

ively between a female and a male cocoon: the difference in size is so small. The cells, moreover, have the same capacity: the diameter of the cylinder is the same throughout and the partitions are almost always the same distance apart. If I open it in July, the victualling-p

of size. If he is a trifle smaller, it is scarcely noticeable, whereas, in the Horned Osmia and the Three-horned Osmia, the male is only half or a third the size

one and all will find what they need, whatever their position in the row. The two other Osmiae, with their great disparity in size between the two sexes, have to be careful about the twofold consideration of board and lodging. And that, I think, is why they begin with spacious cells and generous rat

omae and of the Bees in general were all traceable to a common law. It seemed to me that the arrangement in a succession first of females and then of males did not account for everything. There mu