COPYRIGHT, 1902. BY DODO MEAD & COMPANY

1 GRAY HAIR-STREAK THECLA MELINUS (UNDER SURFACE)

2 RED ADMIRAL PYRAMEIS (VANESSA) ATALANTA

3 OLIVE HAIR-STREAK

THECLA DAMON (UNDER SURFACE)

4 HOBOMOK SKIPPER ATRYTONE (PAMPHILA ZABULON

6 FALCOTE ORANGE-TIP - ANTHOCHARIS (EUCHLOE) GENUTIA

7 THE ZEBRA HELICONIUS CHARITONIUS

8 YELLOW CLOVER BUTTERFLY COLIAS PHILODICE

9 EASTERN TAILED BLUE - LYCAENA COMYNTAS

10 NICIPPE BUTTERFLY TERIAS NICIPPE

stricted, for the butterflies pass their pupal stage incased in comparatively rigid integuments, which form a "chrysalis." They vary greatly in form, some being acorn-like, others very angular, etc., and most are obscure in tint, so as to be easily overlooked, but some are brilliant in color, usually of golden or metallic hues, whence the name chrysalis. Some butterfly chrysalids (Nymphalidae) are simply suspended from the posterior end (Suspensi); those of others (Papilionida) are held in place by an additional strand or girdle of silk (Succincti). Within the chrysalis or cocoon is the immature butterfly or moth, and all the parts belonging to the future adult insect may be found by examination. Breathing goes on through air openings, and the parts steadily develop. "The pupa of the vast majority of moths, of butterflies, and of two-winged flies have the limbs and wings not merely pressed close to the body, but immovably fixed thereto by a general hardening and fusion of the outer skin. Such pupa are distinguished as 'obtect.' But although the limbs are incapable of motion, certain abdominal segments remain free, so that the hind body can be to some extent bent and turned about; and, by means of rows of spines on the abdominal segments, the pupa is in many cases enabled to work its way out of its shelter, when the time for the final change has arrived." Such are styled "incomplete." The pupal stage may be of long or short duration. Many Lepidoptera pass the winter or the tropical dry season as pupa. Some have several broods a year, and in such the pupal stage of the hibernating brood will last longer than that of the others.

The Imago. When the pupa has arrived at maturity, its coverings split and allow the emergence of the "imago" or perfect insect. "Hardly anything in the range of insect life," remarks Dr. W. J. Holland, "is more interesting than the rapid development of the butterfly after its first emergence from the chrysalis.... The imago, as it first emerges, is provided with small, flaccid wings, which, together with all the organs of sense, such as the antennæ, require for their complete development the injection into them of the vital fluids, which upon first emergence are largely contained in the cavities of the thorax and abdomen. Hanging pendent on a projecting twig, or clinging to the side of a rock, the insect remains, fanning its wings, while by the strong process of circulation a rapid injection of the blood into the wings and other organs takes place, accompanied by their expansion to normal proportions, in which they gradually attain to more or less rigidity. The body is robbed of its liquid contents in a large degree; the abdomen is shortened up; the chitinous rings which compose its external skeleton become set and hardened; the wings are expanded, and then the moment arrives when, on airy pinions, the creature that has lived a wormlike life for weeks and months, or which has been apparently sleeping the sleep of death in its cerements, soars aloft in the air, the companion of the sunlight and the breezes."

It is impossible here to go into any description of butterflies and moths. Butterflies, as a rule, are more brilliant than moths, many of them, in the tropics, especially resplendent in metallic hues, rivaling those of the "eyes" of peacock plumes. Moths, on the contrary, are more usually dull of hue, and less given to ap

pearing in open places, even when they fly by day, yet some are high-colored and beautiful.

Both butterflies and moths, and their caterpillars, may resemble to some extent the shape of the object or the coloration of their background, or of other insects. Thus they illustrate most strikingly and copiously various phases of “mimicry" and "protective coloring."

Butterflies, like bees and many other insects, carry pollen from flower to flower, and hence aid greatly in the formation of seeds. See POLLINATION.

Geographical Distribution. Lepidoptera occur wherever plant life suited to the nourishment of the caterpillars is present. They are sun-loving forms and are most numerous in species in the tropics. However, in numbers of individuals, some of the temperate zone forms far outrank any of the others. Some species occur in the Arctic zone and on the tops of snowclad mountains. Certain forms flourish in the far north, in Greenland, Labrador, and Iceland, or on tops of snow-capped mountains. Some species are restricted by temperature or food plant to a very limited area, while others are practically of world-wide distribution. Widely distributed forms either feed on widely distributed plants or can feed on a number of different food plants.

The delicacy of the Lepidoptera has prevented their common preservation as fossils. The Tertiary rocks of the western United States, and the rocks from the time of the British chalk down, have yielded remains of a few scattered species.

More than 50,000 species of Lepidoptera are known, of which almost 7000 occur in America north of Mexico. Of skippers there are two families the large skippers, Megathymidæ, and the smaller skippers, Hesperiida. The butterflies include the Papilionida, Pieridæ, Lycænidæ, and Nymphalidæ, and all other families (over 40) belong to the moths.

Bibliography. For general works, see bibliography under INSECTS; A. Hyatt and J. M. Arms, "Meaning of Metamorphosis," Natural Science, vol. viii (London, 1896); E. B. Poulton, "Neurology of Pupa," in Transactions of the Linnean Society (London, 1890); T. A. Chapman, "Pup of Moths," in Transactions of the Entomological Society (London, 1893); and subsequently W. F. Kirby, Handbook to European Butterflies and Moths (with guide to literature of the order, 5 vols., London, 1895); S. H. Scudder, Butterflies of New England (3 vols., Cambridge, 1889); W. J. Holland, The Butterfly Book (New York, 1898); G. H. French, Butterflies of the Eastern United States (Philadelphia, 1895); A. Weismann, New Experiments on the Seasonal Dimorphism of Lepidoptera, trans. by W. E. Nicholson in Entomologist, January-August (London, 1896); Walker, British Museum Catalogue of Lepidoptera (London, 1854-56); Herrich-Schaffer, Systematische Bearbeitung der Schmetterlinge von Europa (Regensburg, 1843-56); Doubleday and Westwood, Genera of Diurnal Lepidoptera (London, 1846-62); H. J. Elwes, "The Distribution of Butterflies," in Proceedings of the Entomological Society (London, 1894); A. S. Packard, Text-Book of Entomology (New York, 1898); Kirby, Butterflies and Moths of Europe (London, 1906-07); Kellogg, American Insects (New York, 1908); Wood, Butterflies (New York, 1910); Miller, Butterfly and Moth Book (New

York, 1912); Longstaff, Butterfly Hunting in Many Lands (New York, 1912). For works relating to special families and species, see their

names.

PLATE OF BUTTERFLIES AND MOTHS

1. Butterfly's wings, giving names of parts. 2. Wings, giving names of veins and nervules; I, I, internal veins; C, costal veins, SC, subcostal vein; SC, 1, 2, 3, 4, 5, subcostal nervules; UR, upper radial; LR, lower radial; M, median vein; M, 1, 2, 3, median nervules; SM, submedian veins; PC, precostal nervule; UDC, MDC, LDC, upper, middle, and lower discocellulars [after Holland].

3. Resting position of a butterfly. 4. Typical antenna of a butterfly.

5. Resting position of a moth (with typical plumose

antennæ).

6. Mouth parts of a butterfly, showing the extended double proboscis (maxilla, mx), mandibles (m), labrum (1), labial palpi (p), and base of the antennæ (an) between the great eyes.

7. Some of the many forms of lepidopteran eggs: a, one with a lid lifted at hatching for egress of larva. 8, 9. Forms of wing scales.

10. Arrangement of the scales clothing the wing. 11. A caterpillar, showing parts: A, cephalic segments

(head); B, thoracic segments; C, abdominal segments: a, rudiments of the six true legs; b, four pairs of prolegs.

12. Caterpillar of a moth (Stauropus fagi), showing use of prolegs in walking, and extreme development of thoracic larval legs.

13. Caterpillar of a Papilo, showing its retractile osmateria protruded from the neck.

14. Caterpillar of a puss moth, showing retractile anal mastigia extended.

15. Caterpillar or measuring worm of a geometrid moth in an erect and stiffened position simulating a dead twig. 16. Parts of a pupa (chrysalis of a sphinx moth): a, tonguecase; b, eye case; c, trunk case; d, first abdominal segment; m, point terminating abdomen; s, spiracles, or breathing pores, opening into trachea..

17. Process of change of a butterfly (Anosia plexippus) caterpillar into a pupa (after Riley): a, caterpillar just before the rending of the skin; b, chrysalis just freed from the molted caterpillar skin, except the cremaster; c, pupa holding itself in place, head down, by seizing the folds of the shed skin between the edges of its abdominal segments while it searches with its cremaster for the button of silk, attached to a twig or leaf, in which it will hook the cremaster and hang; d, fully developed form of the chrysalis (light green with gold "buttons"). This is an example of a suspended pupa (Suspensi). 18. A belted pupa (Cincti).

19. History of transformation in the Lepidoptera (a moth): a, egg; b, young larva; c, mature larva (caterpillar); d, pupa, within a cocoon; e, mature moth (imago).

BUTTERFLY FISH. A fish of a tropical marine family (Chaetodontidae), so called because of its gay colors and fluttering activity about the coral reefs, among whose growths it chiefly makes its home, and where it lives by capturing small animals, darting about with an irregular agility suggestive of a butterfly in a garden. It is small, short, very much compressed and deep, and the scales extend over the dorsal and ventral fins so that it is difficult to say where the fins merge into the body. The flesh is excellent food. See CORAL FISH.

BUTTERFLY TULIP. See CALOCHORTUS. BUTTERFLY WEED (possibly on account of its gaudy orange-red flowers), or PLEURISYROOT (Asclepias tuberosa). A "milkweed" found in many parts of the United States, which has obtained a considerable reputation for the medical virtues of its root. The root is large, formed of irregular tubers, or spindleshaped branches, externally yellowish brown, internally white, with a somewhat acrid, nauscous taste when fresh, merely bitter when dried. It yields its properties to boiling water and is usually administered in the form of a decoction, fluid extract, or sometimes as a powder. It is diaphoretic and expectorant and has been found useful in the early stages of pulmonary affections, in rheumatism, and in dysentery. stem of the plant is erect, 1 to 2 feet high, and

The

hairy; the flowers a brilliant orange yellow. Unlike most of the milkweeds, it does not secrete latex (the "milky juice" of annuals). See ASCLEPIAS.

BUT TERINE. A name for a butter substitute, used interchangeably with oleomargarine. See OLEOMARGARINE.

The

BUTTER MAKING. The process of making butter from cow's milk is divided into the operations of creaming or separating, ripening, churning, and working or finishing. The fat in milk exists in the form of minute globules in suspension. In the operation of creaming, the separation of these globules from the rest of the milk is affected either by setting the milk in shallow pans or in deep cans in cold water, or by means of a cream separator. In both shallow and deep setting the cream is raised by gravity. The fat globules, being lighter than the water and other constituents of the milk, gradually rise to the surface on standing, carrying with them some of the other constituents also. The time required and the completeness of the operation depend largely upon the size of the fat globules, which differs in the case of different breeds of cows, the larger globules rising more readily. The fat left in the skim milk consists mostly of small globules which failed to rise as soon as the others. fat content of the skim milk is the measure of the efficiency of creaming. In shallow setting in pans the force of gravity alone is relied upon, the milk being set as quickly as possible after it is drawn, and the cream skimmed off after standing 24 hours or longer. The loss of fat by this method is quite large, amounting to about 20 per cent, and the skim milk contains from 0.5 to 1.5 per cent of fat. In deep setting, cans about 18 inches deep are used, and these are immersed or partially submerged in cold water, preferably at about 40° F. The low temperature causes the globules to rise more rapidly and more completely than in shallow setting. The milk is allowed to stand in these cans for 18 to 24 hours, and the cream is then removed from the top by means of a dipper, or the skim milk is drawn off from below, leaving the layer of cream in the can. The latter method is the least wasteful, and by it the fat in the skim milk may be reduced to as low as 0.2 per cent under favorable conditions. The separator has quite generally superseded deep or shallow setting in creameries and in large dairies during the past few years. In this method the cream is separated from the milk by centrifugal force, in a bowl or drum, revolving at a high rate of speed, from 5000 to 8000 revolutions a minute and even more. The milk enters through a tube reaching to the centre and near the bottom of the bowl, where the high rate of speed causes the heavier milk fluid (the serum) to gravitate towards the circumference of the bowl, while the lighter cream remains near the centre and rises to the upper part of the bowl. The skim milk flows out through a side tube, and the cream through a second tube leading from the centre near the top. The operation is continuous, milk flowing into the bowl and skim milk and cream flowing out of it without interruption. The rate of separation varies with the size and capacity of the machine, the smaller hand separators skimming from 200 to 500 pounds an hour, and the larger forms 2000 pounds and over. By means of various appliances within the bowl the sepa