We must not omit to mention, that in some parts of South America, especially in Paraguay, there is a spider which forms a spherical cocoon for its eggs, an inch in diameter, of a yellow silk, which the inhabitants spin on account of the permanency of the colour. It must also be observed that the silk of spiders is useful to the astronomer, who employs the strongest thread (the one, namely, which supports the web) for the divisions of the micrometer. By its ductility, this thread acquires about a fifth of its ordinary length. [Illustration: WHITE WAX INSECT OF CHINA. ] CHAPTER IV. MANUFACTURE OF WAX BY THE HIVE BEE, THE HUMBLE BEE, AND THE WHITE WAX INSECT OF CHINA. [Illustration: GRUB IN CELL. ] [Illustration: [Chrysalis]] The most notable insect manufacturer, after the silkworm, is the common hive bee, which is able to produce three distinct substances, honey, wax, and silk; the first two only being useful to mankind. Persons who have never seen bees in any other than their perfect state, and are unacquainted with the internal economy of the hive, will learn with surprise that the first appearance of this insect is that of a small straight worm, which rapidly increases in size until it touches the sides of the cell which forms its dwelling-place. It then coils itself up, until the extremities meet and form a complete ring. When it ceases eating, the nurse-bees seal up the cell, leaving the caterpillar to spin its cocoon in safety. The silken film in which the insect now begins to wrap itself, proceeds from a spinner, situated in the middle part of the under lip, and is composed of two threads, gummed together as they issue from the two orifices of the spinner. The caterpillar is employed during thirty-six hours in making its cocoon; three days after which it becomes a chrysalis. Over this chrysalis, or rather over the cell in which it is contained, the nurse-bees brood until the warmth of their bodies penetrates, and assists in producing the last change of the insect within. The cocoon, by degrees, becomes attached to the interior of the cell like a lining, and the bee, having its parts gradually unfolded, begins at length to cut its way through the cover of the cell. It is now a perfect bee, and capable at once of taking its part in the labours of the hive. These labours chiefly relate to food, shelter, and care of the young. In the article of food, the bee is a most industrious collector of the sweet juices of flowers, which are converted into the luscious honey with which she stores her hive. She also collects pollen, as an ingredient in the food of the young, and a gummy substance called propolis, which oozes from the poplar, birch, and willow, and which she uses as a sort of varnish and cement to the projecting parts of the hive. [Illustration: BEES GATHERING HONEY. ] [Illustration: HEAD OF BEE. (_Magnified._) ]