ON REARING SILK-WORMS.

THE silk insect affords a display of the wisdom of Divine Providence in the adaption of means to ends, calculated to excite high interest and admiration.

The extraordinary effect produced by this little animal in the short space of six weeks is no less than the conversion of the vegetable substance of the mulberry leaf into threads of rich and durable silk. Well might the Emperor Justinian be astonished to find that the rich and beautiful material of his magnificent robes was first produced and worn by this feeble insect; and well might he repay with munificence the monks by whose exertions the eggs of the silk-worm were smuggled in a hollow cane from India to Constantinople. The hollow cane was the ark whence came out the germ of those numerous tribes of this insect which have spread over the whole of Europe. Let us commence with the eggs of this insect, and trace its operations, its wants, and various changes, till it forms the cocoon, from which proceeds the moth, which in its turn produces the egg.

The Eggs.-The eggs are of a small size. When first laid, they are of a pale yellow colour, but in three or four days turn to a light slate colour, and subsequently to a dull brownish slate colour. Those which remain yellow have not been fecundated, and of course are worthless. The most proper place for keeping the eggs until they are wanted for hatching is a dry cellar. They should be kept in a tight box, to protect them from mice or insects, and dry, so that the mould and mildew may not injure them.

The Hatching, Leaves, &c.-The advance of the season determines the time of hatching the eggs. As soon as the leaf of the mulberry begins to unfold, and you observe that there is a prospect of having a sufficient quantity of food, it is time to expose the eggs to hatch. No other process is necessary than to expose them to the air in a room; they hatch voluntarily in a day or two after the exposure. Various modes are adopted— hatching them in ovens, carrying them about the person, &c.

It is best to preserve those insects for rearing, that come out as nearly at the same time as possible. As soon as the worms begin to appear, lay over them young and tender mulberry leaves; they will soon attach themselves to the leaves, and by taking hold of the stems of the leaves you may remove them easily. They ought now to be supplied with fresh tender leaves three times a day. As the leaves when very young will dry so much in a short time, if exposed to the air, as to be unfit for use, you may put them in a glazed vessel, or keep them covered in a cellar or cool place: by which means the leaves may be kept good for two or three days. Besides, it is well to have always in your house a stock of leaves, sufficient at least for three days provision for your worms in case of wet weather. If leaves are given when wet, they will cause disease. Be careful never to pull the leaves MAGAZINE OF BOTANY AND GARDENING, VOL. III. NO.

when wet, either with rain or dew, except on absolute necessity, and in that case you must spread them and turn them, that the leaves may be perfectly dry before you give them to the worms; rats, mice, spiders, ants, and fowls, are very destructive to the worms: care must be taken, therefore, to keep them out of the way of all such enemies.

The Nursery, Shelves, &c.-Laboratories have been constructed with great care and expense; but, however convenient these may be, they are by no means necessary to success in rearing silk-worms: almost any building will answer for that purpose. I have reared them myself with success in a barn, in my cellar, kitchen, and other rooms of my dwelling house. It was found in France that the cocoons brought to market by the peasants, raised in hovels so full of cracks as easily to be seen through and to admit the air freely, were richer and heavier than those reared in palaces, and in the confined rooms of dwellings in cities. An apparatus consisting of a wooden frame, four feet two inches high, each side; sixteen inches and a half wide, divided into eight partitions by small pieces of wood, which form grooves in which the slides run, and are thus easily thrust in or drawn out of the frame, is worth adopting by those who are begining on a small scale.

The upper slide is of paper only and designed to receive the worms as soon as hatched; the others are of wicker-work, the opening being about a quarter of an inch square; under each of these are slides. This occupies little space and is neat, and the person using it can easily remove the litter. I have used three tiers of rough boards fixed upon upright posts, about four feet in width, one above the other, with a space between of two and a half feet, affording room sufficient to pass all round the frame, so that I could conveniently reach any part of it. In making the shelves, it is well to have the lowest one six inches broader than the one above it, and to make the same difference in the other shelves above, so as to break the fall of such worms as happen to tumble down. A good size for the shelves is to form them about two and a half feet wide, by five or six long, of thin boards, with a piece two inches wide nailed flat on the upper edge along the sides and ends, with legs about a foot long in the corners. The legs should not pass through the table, but leave a part of the hole on the upper side for the feet of another table to set in. Thus contrived, five or six of these tables may be set one above another, and taken down, cleaned, and again set up with facility. One these shelves will accommodate 500 worms. It might

be as well to put old newspapers on the shelves, which might be taken off whenever it was necessary to clean the worms, and then replaced. Thus I have done.

The Different Ages, Moulting, &c.-There are several varieties of silk-worms. The most common varieties change their skins four different times. These changes are called moultings, and the intervening times the different ages. The time requisite for the several changes depends greatly on the temV. MAY, 1837.

L

perature. If the weather is warm, they will generally happen as follows: the first moulting on the fourth or fifth day after the hatching-the second begins on the eighth day-the third on the thirteenth and fourteenth days-and the last change on the twenty-second.

The fifth age lasts about ten days; at the end of which the worms have reached their ultimate growth, being three inches in length, and are prepared to spin their cocoons. Thus thirtytwo days intervene between the hatching and the beginning of the cocoon, and I have known the period retarded to sixty days. These changes will only be noticed by accurate ob

servers.

Feeding, clearing the Litter. &c.-Too many leaves should not be given them at once, and the leaves given should be spread very thin, because, if put on too thick, a great number of the worms when small will run the risk of being lost and carried out amongst the litter.-When the worms are in the first age, you need only clear the litter once or twice, as you find it necessary. During the whole of the first age, the leaves of the young plants of the mulberry, as being the tenderest, are preferable to the leaves of older trees for the food of young worms. It is well therefore to sow some mulberry seed every year, so as to have a succession of young plants. During the temporary sickness produced by changing of the skin, they should be fed with a very sparing hand. The signs by which it is known that worms are sick, and about to change their skins, are these: they hold their heads up, are motionless, and appear to sleep; this should be noticed."

During the second age it is desirable still to continue to feed your worms with leaves from the young plants, as they are still preferable for them. You must now begin to be attentive to clear away the litter from time to time, so as to prevent all danger from its heating, which proves highly injurious, though some people never clear away the litter at all. These insects are remakably fond of cleanliness, which besides helps to enliven them, and give them a keen appetite for the leaves that are given them. The litter is taken away in the following manner: you scatter some fresh leaves upon one corner of the shelf, to which the worms having attached themselves, which they will readily do, you then take up the worms by means of the leaves and stalks they cling to, leaving the litter underneath. Having thus taken up all the worms from that corner and placed them in a clean place, you then clear away the litter from that corner, and carefully sweep together with a little broom or wing all the dirt, which you remove entirely; you then remove worms next adjoining to the clean place thus prepared, and put them into it; in this manner you proceed with the rest.*

During the third age the full grown leaves of the largest tree may be given, though it would be well to reserve the largest and toughest leaves till the last age, when they are most voracious. During the third age, the litter should be removed at least three or four times; worms that die, or appear to be diseased, should be immediately removed.

The same treatment will be required during the fourth and fith ages as in the preceding.-As they advance in age the greate rwill be the proportion of food required, and the oftener the litter must be removed; by these means the process is sooner brought to a conclusion, and the worms always kept in high health and appetite. During the four or five days previous to their rising, the worms consume an incredible quantity of leaves, eating with great voracity, and at this time the labour of tending is most fatiguing. You will know when the worms are ripe or ready to rise and form their cocoons, by observing them with attention when you give fresh leaves. Those that are ripe, instead of eating, avoid the fresh

If the worms are laid on a newspaper, it is easy to take out the newspaper, lay it on a table, and transport the worms, who generally adhere to the leaves and branches, to another newspaper, which is put on the shelf after sweeping it. The litter on the other one may be thrown away.

leaves, and run over them as fast as they can wan derabout, and try to climb; they will look transparent, of the colour of a green gage plum, and somewhat diminished in size.

In the fifth age the worms should have new leaves as often as the old ones are consumed, until they are observed to creep on the leaves without eating. At night they should have a double portion,

Preparations for the Cocoons.-Previous to the rising of the worms, some little arches or cabins should have been prepared of brushwood or broom corn, by setting their branches with their tops spread, pressing against the bottom of the upper shelf to hold them in their position.-The worms will readily find and climb these little trees and spin their cocoons in them; the worms will be three or four days spinning their cocoons, and they will all generally be finished in about eight days. The brush may then be taken down, the cocoons taken off, cleared of the loose tow and prepared for reeling. I have found that the branches of the oak, with the leaves on, answered the purpose of these arches very well, as the leaves are strong, and do not crumble in taking off the silk. They should be cut some days before hand, and be dry when used. Some prefer to have the brushwood entirely stripped of its leaves.

Seed Cocoons.-Those cocoons that are intended for seed. may be stripped of their tow and strung upon a thread—care being taken not to pierce entirely through the cocoons-and hung up until such time as the moths come out, which will be in one or two weeks, when the males and females will couple; they may be taken by the wings in pairs without separating them, and placed on large sheets of paper, (old newspapers will do,) where they are to remain; as many pairs of moths as can conveniently lie on the papers, may be placed there. The room in which these are placed, should be secured from mice and ants, and the sun should not be permitted to shine on them in any stage of their existence; as soon as the moths on one sheet have done laying their eggs, it should be folded up and put in a cellar, or in some cool, dry place, until wanted for use next spring.

The moths are in the form of a grayish white butterfly, and generally begin to lay their eggs in 24 to 36 hours after leaving the cocoon. Each female moth will lay from three to 400 eggs generally handsomely disposed and firmly attached to the paper in a circular form.

Should the eggs be permitted to remain exposed to the warm weather, they will sometimes hatch the same season, and unless another crop be desired, they will be lost. The moths eat nothing after leaving the cocoons, and die in a few days after depositing the eggs.

Diseases of Silk-Worms.-Writers enumerate and describe a variety of diseases to which silk-worms are liable in their different ages, and particularly in the fifth, which all agree to be most critical. But to all these diseases they prescribe the same means of prevention, and the same remedies when they have occurred. It is therefore unnecessary to describe their various symptoms, as it would lead to no good practical result.

The diseases of silk worms generally arise from the want of sufficient air and space, from their not being kept dry, and being fed with damp leaves, and also from their not being kept sufficiently clean, particularly in the fifth age. The fermentation of their litter, the dampness and the bad air which it occasions. are the most frequent causes of mortality among them. The greatest care therefore should be taken to keep them constantly clean and dry, and to give them a sufficient quantity of space and air; a current of air in fine warm days should always be let into their nurseries.

If, notwithstanding all the care taken, some general sickness should declare itself among them, the remedy recommended by the writers, is, to give them a change of air, by transporting them into another room. But this may not always be convenient. It is with these animals, as with our species, easier to prevent diseases than to cure them. If nothing better can be done, the diseased worms must be thrown away. The