After this she came out of the cocoon, and closed the mouth (Fig. 30D), making the opening smaller by degrees. Then she made a little mast (Fig. 30D, _b_), of the use of which Lyonnet admits his ignorance, suggesting, however, that its construction may serve to use up the silky matter remaining after the work is finished, lest it should acquire harmful qualities in the body of the Beetle. The true explanation seems to be that it serves to convey air to the eggs inside the cocoon. On July 17 Lyonnet was rewarded for his patient watching by seeing a larva come out of the cocoon, and the next day some fifty more appeared. What he saw and recorded it is in the power of others to see, if they will imitate his patient observation. The Cocktail Beetle, or Devil’s Coach Horse (_Ocypus olens_), is an excellent specimen of a Land Beetle to examine, for it is of fairly large size and extremely common. Moreover it does well in captivity, so that there will be no difficulty in watching its habits in life, and pickling it for closer examination when dead. During the day these animals usually lie concealed under stones or pieces of earth, coming forth at dusk and during the night in search of food. Occasionally, however, they may be met with in daylight, leisurely stalking a smaller beetle or a fly; then with a dash seizing the victim in their powerful mandibles, which are quite capable of making an impression on the human skin, as those who handle these Beetles unwarily will discover for themselves. [Illustration: FIG. 31.--Cocktail Beetle. _a_, larva; _b_, pupa.] Nothing of an animal nature comes amiss to them, and if they cannot capture living prey, they will make a hearty meal off carrion. This is an advantage to us, for we may feed our captives with dead insects or with small pieces of meat. This Beetle is about an inch long, and of a deep dull black colour. The head is joined to the thorax by a distinct neck, and the abdomen is naked, owing to the fact that the wing-cases are very short. Its wing-cases bear about the same proportion to those of the Margined Water Beetle that a man’s frock-coat bears to a boy’s Eton jacket. And this Beetle may be taken as a good type of a group--the Beetles with short wing-cases (_Brachel´ytra_). The attitude of this animal when irritated or alarmed is well depicted in Fig. 31. It raises its head menacingly and opens its strong mandibles to their full extent, at the same time turning up the end of the abdomen, like a scorpion about to sting. From the last segment it will often put forth a pair of white vesicles, from which is discharged a volatile liquid of disagreeable odour, that probably acts as a defence against insect-eating creatures. The best way to capture one of these Beetles is to pick it up with what Kirby calls the ‘natural forceps’--the finger and thumb. It may be dropped into any convenient receptacle; the small metal boxes in which vestas are sold will answer the purpose very well.