The larva having derived support in the manner above described, for four, five or six days, according to the season[C], continues to increase during that period, till it occupies the whole breadth and nearly the length of the cell. The nursing-bees now seal up the cell, with a light _brown_ cover, externally more or less _convex_, (the cap of a drone-cell is more convex than that of a worker,) and thus differing from that of a honey-cell, which is _paler_ and somewhat _concave_. It is no sooner perfectly inclosed than it begins to labour, alternately extending and shortening its body, whilst it lines the cell by spinning round itself, after the manner of the silk-worm, a whitish silky film or _cocoon_, by which it is encased, as it were, in a pod or pellicle. "The silken thread employed in forming this covering, proceeds from the middle part of the under lip, and is in fact composed of two threads gummed together as they issue from the two adjoining orifices of the spinner[D]." When it has undergone this change, it has usually borne the name of _nymph_ or _pupa_. [Footnote C: Schirach asserts, that in cool weather the development takes place two days later than in warm.] [Footnote D: Kirby and Spence.] It may appear somewhat extraordinary that a creature which takes its food so voraciously prior to its assuming the pupa state, should live so long without food, after that assumption: but a little consideration will perhaps abate our wonder; for when the insect has attained the state of pupa, it has arrived at its full growth, and probably the nutriment, taken so greedily, is to serve as a store for developing the perfect insect. The bee, when in its pupa state, has been denominated, but improperly, _chrysalis_ and _aurelia_; for these, as the words import, are of a golden yellow colour and they are crustaceous; whilst the bee-nymphs appear of a pale, dull colour, and readily yield to the touch. The golden splendour, to which the above names owe their origin, is peculiar to a certain species only of the papilio or butterfly tribe. The higher class of entomologists, following the example of Linnæus, apply the term pupa to this state of the embryo bee, a term which signifies that the insect is enveloped in swaddling clothes like an infant, a very apt comparison. Kirby and Spence have remarked that it exhibits no unapt representation of an Egyptian mummy. Huber's translator says that naturalists of the present day incline to use the name of larva, in all cases where the worm is not seen under its final aspect.