cause the intestine to protrude at the anus, where it can be severed with the scissors. Working from head to tail, with a finger or the roller, squeeze out the body contents. The more fluid portions will be absorbed by the paper, and the whole operation is much quicker and less messy that you would expect. When the skin is as empty as you can get it without bruising it, insert the air tube at the anal incision. If you use a straw, choose one to fit the opening. Run it into the specimen as far as the thorax so that it will act as a support to the limp hide. Fasten the specimen securely by means of a thread tied around it as close to the anus as possible, or by one or two needle points driven into the straw through the skin, as illustrated in Fig. 7., "A". A canula will be somewhat tapered. Insert it as far as necessary to make it fit closely, and time required to achieve this desirable condition will vary with the size and density of the specimen, the temperature of the oven, and the humidity of the atmosphere. Do not leave the specimen in the oven longer than necessary, lest it burn. If you have used a straw to inflate the creature, do not remove it, but cut it off about a quarter of an inch behind the specimen and pass an insect pin through the stub. Remove any needle points which you may have used, but leave a thread, after clipping off the ends. If you have used a canula, remove the clip and loosen the insect with a needle. Withdraw the tube with a cautious, twisting motion. Several methods of mounting "blown" caterpillars are shown in Fig. 8, "A" being the pinned straw mounting already described. "B" is a device for holding a strawless specimen. It consists of a piece of fine silk-insulated copper wire about twice as long as the insect, bent double, with the part nearest the bend wrapped several times around an insect pin. The free ends of the wires are twisted together for a short distance, close to the pin, before being spread apart to produce a long Y a little wider than the insect. To use, cover the ends of the wires with glue, shellac or plastic cement; pinch the wires together at the base of the fork; and insert both ends into the opening left by the canula. The further they project into the specimen, the more support they will give it. When the pressure is released, the wires will spread apart, and be stuck to the sides of the insect by the adhesive with which they are covered. Wire which is too stiff and strong may burst the specimen. At "C" is shown a caterpillar mounted by gluing its feet to a straw, natural or soda-fountain variety, which is impaled upon a pin. Note that any caterpillar mounted as part of a scientific collection is provided with pin labels giving the locality and date of capture, the captor's name, food plant when known and other pertinent details, before being pinned into the cork- lined box beside the adult of the same species. Pin labels and storage boxes are discussed in Leaflet Four. "D" shows how method "C" may be adapted for an exhibition specimen, a real twig with artificial leaves replacing the less artistic straw. If the plant copied be appropriate to the species of caterpillar, the mounting will be instructive as well as attractive. It would be advisable to paint the specimen, since exposure to light will soon bleach it. To minimize the rigidity of the inflated larva, mount it on a spot where its linear posture will seem natural. If you are interested in exhibition mounting, you will learn a great deal about the making of artificial foliage, fruits and flowers from the Museum's Science Guide No. 82, "Building the Museum Group." This you may have for the sum of eighteen cents, including postage, by writing to the Division of Popular Publi- Fig. 8. Methods of mounting dried caterpillars. A, B, and C. Study-collection mountings. D. Exhibition mounting. adjust the clamp to hold the specimen. Since this in no way supports the empty skin, a constant pressure bulb is almost necessary to prevent collapse whenever you stop blowing for a second. Of course, you can stand the oven on end and hang the specimen in it, head down; but this will call for a mechanical means of holding the tube in place, since the heat rising upward from the oven is too great to be endured for long by unprotected hands. Inflate the larva by blowing gently on the other end of the tube, and insert it into the oven through the opening provided for the purpose. The air pressure should be maintained as steadily as possible, but it should not be great enough to distend the specimen further than it could expand in life. Rest the tube in the V of the opening as you blow. From time to time, remove the specimen to see how it is progressing. When done, it should be perfectly dry, hollow, and rigid, so that it can be held between the fingers without collapsing. Its color should be almost natural. The 7