ENTOMOLOGY

RELATIONS OF CLIMATE AND LIFE 99riods. Formerly, this suspension of activity by animal life on accountof cold was called hibernation, which means winter rest. The writer hasshown (Pierce, W. D., 1916, Journ. Agr. Res., vol. 5, PH. 1183-1191)that this same inactivity may be caused by dryness or heat and possiblyby excessive humidity, and that a creature may remain in the samestate of inactivity from the heat of summer through the cold of winterand be awakened from it only by the addition of a requisite amountof moisture at effective temperatures. We must seek other terms thanhibernation, or winter rest, and aestivation, or summer rest. As thisrest consists essentially of an almost complete cessation of all bodilyfunctions, and is a state of insensibility, we may very properly designatethe so-called hibernation as RHIGANES'l'HESIA, or insensibility dueto cold. This state may be acquir~d naturally as winter sets in, or maybe artificially induced at any time of the year by lowering the temperature.The temperatures inducing RHIGANESTHESIA are groupedinto the LOWER ZONE OF INACTIVITY, or the ZONE OF RHIG­ANESTHESIA.As the temperatures increase, a creature in the state of rest orrhiganesthesia, commences to show slowo movements of the body fluids,and slight jerky motions, lvhich increase with increase of temperature.This awakening or anastasis, when caused by temperature change, is aTHERMANASTASIS.The approximate point at any given humidity at which thermanastasisbegins is the ZERO OF EFFECTIVE TEMPERATURE. It must befirmly fixed in your minds that there is not a single zero of effectivetemperature, as so often claimed, but a different one for every degree orportion of a degree of relative humidity. In other words, at one humiditythe awakening may occur at one temperature, and under other conditionsof humidity the temperature may be considerably higher or lower. Thesepoints can be connected by a curve which represents the lower limit ofthe ZONE OF ACTIVITY, or the THERMOPRACTIC ZONE, meaninga zone of effective temperatures.Many authors have manifested considerable confusion in their writingsand have «;ven claimed that other authors were incorrect because acertain developmental period or reaction was accomplished in their experynentsat a given temperature in a certain period of time while theother investigators obtained totally different results. A man workingin 0. moist coastal section could not justly compare his results with thoseof a man working in a drier section unless the conditions of humidity wererecorded also. For this reason, the writer has maintained that laboratoriesattempting to correlate temperature with life historY, must at leastbe equipped with maximum and minimum thermometers and a slingpsychrometer for determining humidity, and that accurate results arE