Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/205

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and glofly outer baric of many trees, as that of the cherry, &c. 1 heir colour is ufually a faint brown, fometimes it approaches to a coffee colour, fometimes to a bright chefnut, but more frequently it has fomethiiig reddifli in it. The young fhoots of the peach-tree are often covered with . thefe on all fides ; fometimes they are more diftant and fewer in number. All that one fees of this kind at this feafon have the lame lifelefs appearance, and all appear perfectly motion- lefs; but they are, however, of very different ftates and con- ditions, for ufually fewne are in full life and vigour, others al- ready dead, and others even the fpoils of thofe of a former feafon, which remain in the places on which they died with- out the leaft feiifible alteration in their appearance. Thofe, however, on the old wood may be judged to be dead ones, but thofe on the branches of the prefent year are ufually found alive and well. The dead ones, if touched, appear as a mere film, and fall off in their fcales from the branch; but the others, if crufhed, yield a vifcid juice, like that from the crufhing of other living infects. The living anima! is at this feafon fo clofely affixed to the tree, that it is not eafy, by the fingers alone, to feparate them without deltro;, ing them ; but with caution they may be eafily railed unhurt, by getting the point of a knife between them and the bark : in this cafe, the part of the tree from whence they are raifed is feen covered with a cottony matter. The belly of the animal, which is naturally applied againft this downy matter, is at this feafon puffed up, as it were, and feems as full as it can well hold. A little later than this feafon, if others are raifed from the tree, it is then lefs eafy than before to know them to be animals.

If ina fortnight, or a little more, after the time of their being as full as can be, they are removed from their place, they then make no other appearance than that of one of thofe dead and dry ones before mentioned, no more of the full flefhy appear- ance is to be feen, but they appear merely a thin flake of tor- toife fhell, or fome other fuch fubftance, covering a vaft num- ber of fmall bodies clofe Lodged together, but as loofe horn one another as fo many grains of fand, and fall to the earth on raifmg the fhell, unlefs it be done with great care. Thefe fmall bodies are fomewhat reddifli, and when examined by the microfcope, the oval figure of them will not let one doubt but that they are eggs; and the whole infect might now appear to any one no other than a cafe prepared by fome animal for the fafety of its eggs. A little afterwards, if the animals in this ftate be examined, the fhell is found, inftcad ] of eggs, filled with fmall living infects, among a quantity of loofe powder. No more eggs are found entire : thefe are the animals hatched from them, and the fhelis are what now make the loofe powder.

The galls, and fuchexcrefcences on vegetables, are always found pierced with holes, out of which the fly uTues, which, in its worm ftate, had been nourifhed there; and that there might be no refemblance wanting in thefe creatures to galls, their fkins are often found pierced in two or three different places, nay, and flies are feen fometimes iffuing out of thefe, which had lived within them in the worm ftate. That thefe are of a certainty animals, and not galls, is evinced, however, beyond doubt and difpute, by railing one of them in an intermediate time between that of its being found full of eggs, and that of its appearing only diftended and fwelied; becaufe in this in terval the animal will be found in the aft of laying them, and may be feen doing fo. The young animals hatched from thefe eegs are for many months feen in the condition of other fmall infects; but as they become full of eggs, they fwell, and, by degrees, !ofe their true fhape : they grow in fize as thefe eggs grow in them, and when full grown and ready to lay, their bellies are fmooth and even, and the rings of which they are compofed are not to be diftinguifhed: in another ffate it is eafy to diftinguifh thefe they are five in number, and the pallage for the effgs is in the laft. The animal has fix legs, which not having been ufed of a long time, are found clofely applied to ics belly; and a little above the firft pair there may be feen a fmall prominence, which is the part by which the creature takes In its nourifh- imnt. The cottony bed that lies under thefe infects on the tree, fhews extremely plain the imprefiions of all the parts of the animal ; the legs, rings, £?r, are ealily diftinguifhable here.

It is a general law of nature, that infects perifh when they have done all that was necellary for the multiplying of their fpecies ; that is the cafe alfo with this little animal. It lives hut a little while after it has laid its eggs, and it.-; dried body makes an excellent covering and defence for them ; and what is very remarkable is, that as this infect is now immoveable, and cannot draw itfelf over its egg, they are not thrown out behind its body, as the eggs of other animals ; but as they are laid, arc drawn under the belly, and evenly arranged there. The eggs are ten or twelve days before they hatch, and when hatched, the young animals remain quiet under the cover of their mother's carcafs for feveral days.

After fome time, when their parts are duly flrengthened, they get out and enjoy their liberty: thefe new-born infects are fo extremely fmall, that it requires a microfcope to obferve them ; but they are in nothing like what their parent was, or what

they are to be hereafter; they ate very nimble and active, grid march backward and forward with prodigious' fwiftnels. 1 here is now nothing fmguiar in their form ; they are fome- what flattifh, and of an oval figure, and have two horns or antenna, as well as their fix legs, very eafily diftinguifhable. The number of young ones hatched by each parent is verv great, often not lefs than four thoufand. The yewig ones have an eafy paflage from under the fhell made of" their pa- rents body in this, that the hinder extremity of that fhell is fpht, and is not, as are all the other parts, "faftened to the branch.

It has been fi:ppofed, that the young gali-mfecls eat up their mother's body, and eat holes through it to get out ; but this is by no means the cafe ; the opening already mentioned gives them a free paflage, and the holes we fometimes fee on the hacks of thefe animals are ever made by extraneous animals, fmall flies, which have in the worm ftate "grown and been nou- rifhed within the body of ths animal, as they do in the bodies of caterpillars and many other infects; and which, when hatched into the fly ftate, make themfelves thefe holes for their efcape.

It is ufually about the beginning of June that the young infects get at liberty from under the body of their parent; they may then be found running very nimbly ail over the branches of the tree, but are not diftinguifhable otherwife than by examin- ing the branches with a microfcope. 7'he branches thus co- vered with thefe young animals, are in a few days cleared again, and the infects found in form of fmall fcales, covering the leaves, and now large enough to be feen by the naked eye. They are of different colours; fome white, fome yellow, fome greenifh, and fome reddifh: and in this ftate they are to very flat, and withal fo immoveable, that they may naturally be miftaken for the fkins quitted by fome infects ; but on crufhing them with one's nail, a yellowifh juice is always fqueezed out, which fhews them to have been real animals; but the greater! proof of it is to be had from ohfervation, for after fome time they will be found again very fwiftly in motion.

Thus thefe little animals, after being hatched on the branches, run over them in fearch of the leaves for nouriihment : they do not eat thefe, however, but fuck the juices from their veftels by a fine trunk, and it is only while they are employed in this that they in this ftate appear immoveable. Thefe trunks are placed a little above the firft pair of legs ; but we are not to look for them in the young infects, it is only in the full o-rown ones that they are diftinguifh able, and in thofe not without difficulty. In thefe, however, with attention, one may ob- ferve in this part a fmall hollow, or fhort Hefhy pipe, out of which the infect can at pleafure thruft a fine white trunk, as fmall as a fine hair, and of half the length of its body. The more careful gardeners always clear their beft fruit-trees from thefe infects, efpecially their orange-trees, well know- ing that they drain the juices of the tree, and will fometimes even kill it. This is not to be fuppofed owing to what juices they take in for their nourifhment alone, but they occafion the wafte of a vaft deal bcfides : under feveral peach- trees, and par- ticularly under diftinct parts of them which are loaded with thefe gajl-fafe&s } it is common in the middle of May, or be- tween that and the beginning of June, to fee the earth as wet as if newly watered, while that all about is dry ; a very lar°-e quantity of the juices of the tree continually making their way through the holes left by the trunks of thefe innumerable little animals. At the fame time that one finds the young gall-wfefts on the leaves, one finds them alfo on the young fhoots of the peach-trees, and the reafon is the fame, that thefe parts are more eafily pierced by the tender organs of the young animals than the branches and harder parts of the tree. Their backs in this ftate are not fmooth and even, but, examined by the microfcope, are found to be wrinkled and channelled in a beau- tiful and regular manner.

Not only the gail-i»fe£7s of the peach, but all the ether fpecies, after a certain time, become immoveably fixed to the place where they are, and no longer able to ufe their legs. Their growth is very flow from the time of their hatching, through the months of July, Auguft, September, and October; at the beginning of November they are found fomewhat enlarged in breadth, but they are yet no thicker, and at this time they are all become of the fame colour, which is fomewhat reddifli.

In the beginning of March they begin to fwell and be filled with the growing eggs ; their backs become a little convex, and, viewed with a microfcope, appear covered with little tu- bercles ; and one may, at this time, perceive feven or eight long threads, which run from feveral parts of their bodies : thefe fatten themfelves to the branch at a diftance from the creature, and fix it immoveably in its place. In the beginning of April they become much more convex, and tho' they can no longer walk about, they yet have at this time fufficient motion to fhew an animal life. At this time, by very flow motions, they change their fkin ; and it is after this change that they affume fo exactly the figure of galls, and grow fo very quickly to their full fize. Seven or eight days now make fuch- a change in them, that they are not to be known for the fame animal; but it is not till the beginning of May that they ar- I rive