ENTOMOLOGY

100 SANITARY ENTOMOLOGYbased only on a recording hygrothermograph, checked by the abovementioned instruments.The great bulk of work naturally is upon the reactions which takeplace in the zone of activity.It must not be forgotten, however, that control work depends oftenupon a correct knowledge of the lower zone of fatal temperatures, andthat successful storage of breeding material, until the investigator isready to use it, depend~ often upon a knowledge of the requirements ofrhiganesthesia. .Following the awakening, the body takes up all its natural functionsand we must assume that sustenance is available. The lirst activities,at temperatures just above the zero of activity, are naturally verysluggish and this state of sluggishness may be known as RHIGO­NOCHELIA, or sluggishness caused by cold.Some creatures are very sensitive to cold, usually when the humidityis high. Pain produced by the application of cold is called CRYAL­GESIA. An abnormal sensitiveness to cold is known as CRYESTHESIA,and a motbid sensitiveness as HYPERCRYALGESIA. These sensationsare probably only experienced with a descent of temperatures.In the zone of effective temperatures or thermopractic zone thereis a point or a dmall restricted zone of temperatures at which all activitiesare most effective, that is, the greatest amount of work is accomplishedwith the least amount of exertion and the least loss of energy.This is the so-called OPTIMUM, or perhaps better, PRACTICOTATVM,meaning most effective. As temperatures ascend to the practicotatumany given function is performed in proportionately shorter time. Asthe temperatures ascend above the practicotatum a particular functionmay be exercised more rapialy but less accurately or less effectively, asfor instance, more eggs may be laid but fewer hatch: but the activity isfeverish and soon exhaustion takes place, or the individual graduallybecomes more &tupid and sluggish. This heat sluggishness is thereforecalled THERMONOGHELIA.Different reactions to heat may be experienced and these have allreceived .appl'opriate designations. As for example, a stifling sensationis called THERMOPNIGIA; an unusual sensibility to heat THERMAL­GESIA, and a more intense sensibility HYPERTHERMALGESIA. Theability to recognize changes of temperature is THERMESTHESIA,and its extreme is designat\!d as THERMOHYPERESTHESIA, anabnormal sensitiveness to heat stimuli. A fondness for heat or requiringgreat heat for growth is calle..l THERMOPHILIC, while resistance toheat is called Tf.IERMOPHYLIC. When a stifhng temperature is experiencedrapid breathing or 1 ~IERMOPOLYPNEA is often experienced.Contraction under the a~ ion of heat is designated as 'rHER-