particular with regard to their figure. The bafe of each cell is formed of three rhombs, as we have already faid, almost always equal. According to the measurement I have made of them, each of the obtufe angles, is no degrees, and each of the two acute ones is confequently 7o. Thefe three rhombs are inclined to one another, and are joined by the fides which form one of the obtufe angles. The mutual inclination of these rhombs makes a folid angle, which on account of the general uniform equality of the thombs, is fituated in the axis or centre of the cell. The fix other fides of the fame rhombs, befides three obtufe angles form likewife three other anglès by the reciprocal inclination, which forms their junction at the two acute angles. Thefe fix equal fides of the three rhombs are fo n any bafes on which the bees elevate the walls which form the fix fides of each cell. Each of thefe walls is a trapezium which has one acute angle of 70 degrees and an obtufe one of an hundred and ten; the two angles of the trapezium which are at the mouth of the cell are right angles. We muft obferve here that the acute angle of the trapezium is equal to the acute angle of the rhomb at the bafe, and the obtufe angle of the fame rhomb is equal to the obtufe angle of the trapezium. The fix trapeziums which form the fix fides of a cell join one another at equal fides, and are connected to the thombs of the bafe; thus the obtufe angles of the rhombs are contiguous to the obtufe angles of the trapeziums, and the acute angles of thefe laft to the acute angles of the former. Such is the ftructure of each cell.

I come now to the manner in which the two ranges of cells conflituting the comb are formed, and the way in which the cells are joined together. Imagine to yourfelf in the first place, feveral other bafes fimilar to thofe we have defcribed; fuppofe farther, thefe bales to be applied to one another in fuch

man

manner that the fimilar angles of the one fhall correfpond to the fimilar angles of the other, and fhall join together exactly. In fuch a cafe two of thefe bafes being joined to a third, three rhombs of thefe three different bafes will form the bottom of a new cell fimilar to the first, with this only difference, that the concavity of the folid angle is turned to the other fide of the comb, where there is another range of cells oppofite to the firit. By the junction of fix bafes with a feventh, there will be formed three new ba fes, which will have the concavity of the folid angle allo turned in a contrary direction to that of the feven bafes. Laftly the twelve new bates united to the eight preceeding ones form nine others with the concavity of their angle oppofite to that of the twelve. By this wonderful ftructure are formed the two ranges of combs. of combs. Thus there are three lines of rhombs on three different planes, fo well executed that feveral thoufands of rhombs of the fame line all reft on the fame plane. Is it not truly furprifing then, that fo many thoulands of animals, aided by natural inftinct alone, fhould agree together in forming a work fo difficult, with lo much order and regularity?

Bees do not give their cells fo determinate a ftructure without defign. I have faid that each bafe is formed of three rhombs, and that on each fide of thefe rhombs there is a wall which ferves as a fide to the oppofite cell. Those three walls, befides ferving as a fide to part of a cell, likewife ferve for a fupport to the bafe of the oppofite cell, and fupply the defect aritmg from the great tenuity of the work. Moreover, the concavity of the folid angle which is in the middle of the bafe, ferves by an admirable effect of divine providence to collect into a small space the particles of honey, which the Bees daily furnish to the little larvæ, as I fhall afterwards fhew. If the bottom had not been difpofed in this manner, the honey which is at

first fluid, would have run out, and the embrio would have perished for want. It is not the figure of the bottom only which is favourable, many advantages arife from the number of angles in the rhombs. On the fize of them depends that of the angles. of the trapeziums which form the fix fides of the cell. Now, as the acute angles of the rhombs are 70°. 32′ and the obtufe ones 109° 28' thofe of the trapeziums contiguous to them, must be of the fame degrees ref pectively. Besides, by this number of angles in the rhombs, the folid angle of the base is equal to each of the three folid angles made by the obtufe angle of the rhomb, with the two obtufe ones of the Trape ziums; from this greatnefs of the angles, therefore, there refults not only a greater fimplicity in the work and greater facility for the Bees, who thus make ufe of only two forts of angles, but likewife greater fymmetry in the difpofition and figure of the cell.

The figure which Bees give to their cells is a regular hexagon. Pappus, a celebrated Geometrician of the second century, has obferved that it looked as if thefe little animals had a particular acquaintance with geometry, when they gave fuch juft proportions to their cells. Nor could they have chofen a figure which would have afforded them a greater number of cells in the space contained in their hive. The property of this figure is that many united together completely fill up a fpace round a certain point without leaving any void whatever. The fame property belongs to two other figures, to wit, the equilateral triangle and the fquare. But neither of these have the capacity of the hexagon. It is therefore with great wisdom, continues the fame Geometrician, that Bees make ufe of that in preference to every other figure. For if the fame quantity of matter is employed in the conftruction of a triangle, a fquare, and a hexagon, this laft will contain more honey than the others, The

The fecond example of industry and fagacity in infects fhall be taken from wafps, thefe animals con ftruct their neft, either in the earth, or fufpend it from fome new building: They do not begin their fabric like Bees at the top; but like ordinary architects they lay their foundation, and raise the fuperftructure in the common way. The nefts of all the fpecies are not of the fame fhape. Some are of the figure of an oblong, fome of an oblate fpheroid : fome are conical, with the apex irregular and truncated, fomething like that of certain fea fhells, and fome resemble a bottle with a long neck. The cells in the greater number of wafp-nefls are hexagonal, and furrounded externally with a white integument of a woody fubftance refembling the dry pods of kidney-beans. The upper part of this integument ferves as a roof to the whole edifice; it fecures the neft from humidity, which in running along it, might incommode the wafps. The fides ferve as walls to defend the inhabitants from injury; and the under part is as it were a bafe to the whole fabric; if the integument is removed, the infide difcovers fix ftories at equal distances from one another. But leaft one fhould fall and demolish those below it, each story is fupported by feveral columus which are broad at the bafe, and grow broader again at the top, fo as to form a kind of arch.

The fame elegance is not lefs remarkable in the ftructure of thofe nefts which are fhaped like a bottle with a long neck. The external cover is thin, like transparent vellum. The learned Aldrovandus, having cut one of these nefts longitudinally found it defended with three other integuments which fike the first, were of the fhape of a bottle, but without the neck. In the centre of all thefe covers, he found feven hexagonal cells. Q 2

From

From the nets of wafps I pafs to the fubterrraneous vaults of ants. Thefe infects have a common ftorehouse and no ant makes any provifion for its own individual ufe. This ftorehoufe is divided into feveral cells, the avenues to which correfpond to one another. They are extended fo far within the earth, that neither rainnor fnow can reach them in winter. The caverns of human formation are far lefs artfuily and fkilfully contrived than thofe of thefe little animals. When they are completely finished, any attempt to deftroy them is vain for their excavations are fo extenfive that when once the entrance is demolished, it is not pos fible to trace the turnings and windings of their labyrinth.

The manner in which fome infects form to themfelves a habitation on the leaves of plants must not be omitted here. The tube through which they lay their eggs is at the fame time a fting with which they puncture the leaf they mean to lay them in. But left the larvæ fhould be encumbered for want of room, they difcharge a certain fluid into the hole which occafions a tumour or elevation on the leaf, in which the young are at their eafe. Thefe tumours vary in appearance; fome are like hard fhells, fuch as the Aleppo galls; others like little foft balls; fome are fcaly, others fmooth, and fome hairy; as to fhape, fome are spherical, others in the figure of a

cone.

But it is not in the ftructure of their habitations. alone, that infects difplay their fagacity and induftry; the aftonishing precautions they take to fecure themfelves from injuries of every kind, are no lefs demonftrative of these qualities. Such of them as difagree with wet, avoid it with the greatest dexteri ty. Is wind hurtful to any of them? the places they frequent, and the ftructure of their nefts, fufficiently