February 5, 1886.] 



SCIENCE. 



127 



even weeds were cut clown, and the inner parts 

 eaten out. 



In the houses the struggle for existence of these 

 long-tailed invaders was truly amazing. In many 

 of the dwellings hundreds were killed in a single 

 day. The cats could contribute but little aid, fight- 

 ing such a plague ; for not only were many of the 

 rats so large that it would have been an unequal 

 contest, but by their great number they drove the 

 cats actually from the houses, not to return until 

 the plague was passed. Nothing, except what was 

 composed of iron, stone, or glass, was spared from 

 their destructiveness : furniture, clothes, hats, 

 boots, books, — every thing bore the traces of 

 their teeth. They gnawed the hoofs of cows and 

 horses in the stables, literally ate up fatted hogs, 

 and often bit away the hair of persons during sleep. 

 They penetrated all apartments, and gnawed 

 their way through boards and walls of houses. 

 Ditches that were dug about granaries did not suf- 

 fice : the mice would climb over each other in 

 some corner or other, and thus reach the top. 



The foregoing account of one occurrence in 

 Eourengo will suffice to show to what an extent 

 the plague reaches. The same province had suf- 

 fered similarly in 1843 and 1863, and in all proba- 

 bility will again in 1889. Our astonishment at the 

 strange appearance and disappearance of such 

 swarms of animal life is greatly increased when 

 we perceive in what a close relation of cause and 

 effect it stands with the presence or absence of 

 food-supply ; and probably nowhere among the 

 vertebrate animals is the relation more apparent 

 than here. 



This food-supply is derived from the seeds of a 

 large bamboo-grass (Taquary or Cresciuma) grow- 

 ing throughout Brazil. This grass grows in dense 

 thickets to the height of thirty or forty feet, and 

 bears a very large quantity of seed. Its natural 

 history is remarkable. At regular intervals, vary- 

 ing in the different species from six to thirty 

 years, it matures and blooms, and then disap- 

 pears. Yet more remarkable is the uniformity with 

 which it attains maturity throughout an entire 

 province, if not the whole southern part of Brazil. 



Similar plagues, though far less in extent, have 

 occurred in Europe, in which the field-mice un- 

 accountably appeared in greatly increased num- 

 bers. One may well think what would be the 

 result were these little, almost insignificant 

 creatures everywhere in such wise to take the 

 ascendency. When one considers that on an aver- 

 age of every one or two months from five to eight 

 young are born, and that these young become 

 mature in a few months themselves, he will not 

 be surprised to know that a single pair of the com- 

 mon field-mice, in the course of a single summer, 



would increase to twenty-three thousand individ- 

 uals. Could all the conditions which now keep 

 them in check be removed, every living thing 

 upon the earth would be consumed in a half- 

 dozen years. 



BEE-HIVES AND BEE-HABITS. 



One of the substantial improvements in bee- 

 hives made in the last few years is the arrange- 

 ment whereby the frames holding the combs can 

 be quickly and easily turned up side down. The 

 best arrangement of the several tried is where the 

 rectangular frame holding the comb revolves on 

 pivots fastened at the central point of the end- 

 bars, within a half-frame just enough larger to 

 permit the full frame to turn. The half-frame 

 has the projecting top-bar of the usual Langstroth 

 frame, and the half end-bars receive the pivots 

 of the inner frame at their lower ends. Two 

 years' experience shows me that these frames are 

 a success. 



But why this inversion of frames and combs in 

 the hives? As is well known, bees only attach 

 their combs firmly at top and upper portions of 

 the lateral edges. It is probable that in past ages 

 our honey-bees attached their combs to limbs of 

 trees, as Apis dorsata does to-day, and as our 

 honey-bees do in exceptional cases : hence the 

 strong instinct to attach firmly above, slightly at 

 the sides, and not at all below. By inverting the 

 frames we take advantage of this habit, and 

 secure firm attachment on all sides, thus making 

 the combs secure for shipping, and less apt to 

 break out when we are extracting or manipu- 

 lating them for any purpose. 



Another invariable habit with bees is to place 

 their brood below the honey in the combs. Thus 

 we always find honey at the top of the comb, and 

 the brood at the bottom. Every bee-keeper is 

 also aware that it is not always easy to induce 

 the bees to leave the brood-chamber below, and 

 pass to the sections above, when we desire to 

 secure the comb-honey. But it is found, that if 

 we invert our frames just as the honey harvest 

 commences, thus throwing the honey below the 

 brood, the bees at once, true to their instinct, 

 pass into the sections, as they wish honey 

 above their brood ; and so we not only get the 

 freshly gathered stores, but the honey previously 

 stored in the brood-chamber carried into the 

 sections above, just where we desire it, and all 

 space below vacated for the brood, which is also 

 desirable. 



Not only is it desirable to invert the brood- 

 frames, but the sections as well. This secures 

 more firm attachment of the combs in the sec- 



