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with difficulty comprehended; I have therefore thought it necessary, to represent, by the annexed p ate, the figures which the author describes.
The structure of a cell seems at first fight very complicated, though it is made up of only two different pieces; the first is, the rhomb. Fig. I. the obtuse angles of which, according to M.Maraldi, are each of 1090 28', and the acute ones, A and C, each of 70" 31': the other is the Trapezium, Fig. II. the fide of which, G H, is equal to one of the tour sides of a rhomb; the side, G E, equal to the depth of the cell, together with the hollow of its base; the angle, H, equal to each of its obtuse angle?, and the angles E and F are right angles. Three rhombs, equal to ti-at of Fig. I. form together the base of a cell, and six of the trapeziums compose its sides.
In order to comprehend how these rhombs form a base, imagine the three rhombs, I K L, Fig. III. pi iced on the fame plane, so that any three obtuse angles stull meet in one point, M} then, leaving these three angles in their point of contact on the plane, raise the three angles, N O P, so that the side, M QJhall unite with M R, the side M S, with M T, and the tide M V, with M X, then, from the junction of these three rhombs, thus elevated, there will be formed, the lolid concave angle, Y, Fig. IV. which, turned upside down, will be the solid convex angle, Z, Fig. V. the first of which will be the base of a cell, having its mouth Uppermost, and the other, of a cell having its mouth downwards. Place, on the fix external sides, i, 2, 3, 4, 5, and 6, of these three rhombs united at the base, Fig. IV. as many such trapeziums as we have described, raised perpendicularly to the plane, so that, their acute angses shall meet the acute angles of the rhombs, and the obtuse angles of the rhombs, the obtuse angles of the trapeziums, which may be easily done, by turning the six sim lar trapeziums, one within the other, alternately outwards, then, by the union of these nine piece, will be formed, the hexagonal cell, represented in two different situations, Fig. Vi. and VII. to give a more distinct idea of it.
Now, to know how several cells are connected, imagine, in the first place, three concave bases. B A F 1), B D E C, B C G A, F g. VIII. such as we have described, and set upon the fame plane. If you join them togJther, each by the obtuse angle of one of their rhombs, so that the tlufce
angles angles you have taken, shall meet in one point, B, Fig. IX; then their sides, B A, B D, B C, will unite and become common, in the fame manner as the traptziums which yo-j are afterwards to raise on them, joined to the other trapeziums, placed on the external sides of the three united baies^ will form three contiguous cells, as in Fig. X.
It will be easily conceived,-that, by joining in the fame manner, other bases to the three here mentioned, they will become the bottom of as many new cells as may be joined to the first, by their common sides, and this may be carried on at pleasure.
It remains to know, how the bases of cells make part of the basts of those opposite to them. For this purpose, consider again, the three united bases of Fig. IX. which form each a solid c6ncavi' angle, K-1 H. You will iee, that, by the union of the three rhombs, A D, U C, and C A, which meet in B D, B C, B A, they conspire to form in B, a solid concave angle, equal to each of the three solid concave angles, K I H, the position of which is reversed. It is this angle, B, which makes the bottom or base of an opposite cell, and the six exterior sides, A K D I C II,. of the three rhombs, A D, D C, CA, which compose this angle, serve for support to the six trapeziums, which should be raised on them, and form by the union os their sides, a cell resting on three others opposite to it, as in Fig. XI. where the cell is represented erect, the better to shew the way in which a cell rests on three.others. And, as by joining many basest the angles of which are solid and concave, these bases, by the junction of their external sides, likewise form convex angles, similar to the first, it follows, that several bases of cells united, which belong to one of the rows in a comb, form by their junct'on, several of the united bases of theopposite row. Thus, in Fig. XII. the union of the sevenconcave bases, A, B, C, D, E, F, G, form the convex bases, H, 1, K, of the three opposite cells.
To give a more distinct idea, still, of th« manner in which the two. rows of cells in a comb, are placed on the common base of the comb, I have added figures XIII and XIV. Fig XIII represents the plan of a part of the base of a comb; the hexagons, marked with dots, incLcate the position of the cells of one row; and the hexagons with lines, that of the other row. Fig. XIV. is a section of the fame comb.
PlGB Page J 24,1. 33.
These tumours vary in appearance. These tumours are generally named galls, and are of many different knds: the gall-nut, so well known for its various uses, is one species of it. M. de Reaumur describes several of them, in his Mere'ires, Tom III. his observations are exceedingly curious, and deserve to be read.
Page 125,1. 4.
Choose a place, where they may be secure. That place of retreat is generally the earth; the greater part of insects, which pass the winter without eating, and in their nymph or chrysalis state, retire into habitations which they make there, each in its own way.
Page 125,1. 30. Or by the moufh or abdomen. It is not properly by the mouth, that these insects spin their webs; it is by an apparatus which they have under their mouth. Spiders, and the insects of the genus Hemerobius, draw, from the extremity of their abdomen, the fdk of the coques in which they inclose themselves. Some species, likewise, of Dytisci, do the same, in order to construct the nests in which they lay their eggs.
Page 125,1. 31.
Or by the abdomen. This is the way in which spiders extract the matter of their webs. Those larvae, called by the French, Pucerons-lions, likewise draw from the extremity of their abdomen, the silk of which they make their coque, and in which they inclose themselves. Some species of Dytisci likewise do the same to fabricate the coques in which they deposite their eggs.
Page 125. 1 34.
Others are coarser. Spiders have the power of spinning (heir threads, either fine or coarse, as they please, by drawing from their bodies, as many threads as the occasion requires, and joining them together: those which spread their nets in garden?, can even spin two sorts of threads, the one glutinous, the other not: this we can assure ourselves of, by throwing dry sand on their web: we shall find, that the sind will stick only to those threads that turn spirally, but will by no means adhere to those that run straight across the web.
Page i26, I. 12.
As Jki'ful dyers. It is not in the option of insects, to paint or vary the colours of their silk, at their own pleasure; this depends on the nature of the silky matter which is formed in their entrails. It is this, and not the insect, which gives the colour to their thread. Beside?, what is said here, of the beauty of these colours, is applicable, only to a sew of these animals; the silk which molt of them spin, is of a very ordinary colour, and much inserior to that which a good dyer could give them.
Page 127,1. 7.
The "wife form of government. What authors have advanced, on the constitution and government of bees; oil the authority of their king; on hi? sldll in the art of reigning, on the obedience paid by his subjects, and on many 0ther things of this nature, is so sine, so marvellous, that it' ceases to be probable. Suppose these circumstances to be nothing but ingenious sictions, as there is every reason to believe, it would not be difficult to trace their origin. People have at sirst admired the art with which bees construct their combs and have, from that, conceived very high ideas of them: they have seen them living in society, and labouring in various ways for the common good; from this it would be inserred, that they have laws and established ranks: having found in their swarms, some bees larger than the rest, these would be considered as kings; seeing those surrounded by a number of other bees, these would be courtiers or guards, or subjects coming to receive orders, and to execute them; in a word, no particular has been observed, in the economy of bees, that has not received an interpretation consormable to the high ideas conceived of them, and to the monarchical system, under which it seemed certain, that they lived. But, what would be our surprise, when, after having attended more closely to the behaviour of this king, and having dared, even to lay hands on his sacred person, to sind his body sull of eggs, and to see his principal occupation, that of laying these eggs in the empty cells! From these circumstances, unprejudiced per