loa 



SANITARY ENTOMOLOGY 



temperature-humidities which cause death — this whole zone is the fatal 

 or OLETHRIC ZONE. All conditions of life lie within it, the next zone 

 being that which includes Rhiganesthesia, Xeranesthesia, Thermanes- 

 thesia, and Hygranesthesia ; the whole zone therefore being the ANES- 

 THETIC ZONE, or zone of rest, which includes the conditions known 

 as hibernation and aestivation. Within this is the THERMOPRACTIC 

 ZONE or zone of effective temperatures, which is naturally made up of 

 sub-zones representing degrees of activity, as the NOCHELIC SUB- 

 ZONE of sluggish activities on the outside and the PRACTICOTATUM 

 at the center. 



si/cctsTCD cumcs Of TNC BESPansts OFmmcmmcMii ramtini 

 TCMP[«kTusrs WITH cmm kwl nam nwnc m a sasu . 



Fig. 9 



Temperature and humidity affect every bodily function of every 

 creature of the plant and animal kingdom. Some creatures may love 

 cold, some heat, some dryness, some moisture. The pattern of their 

 reactions will therefore shift from one place to another on the chart. 

 Some creatures may be so resistant to cold that fatal temperatures are 

 never normally experienced and rarely artificially. Some may be very 

 resistant to dryness and others capable of standing any degree of hu- 

 midity. In case of plants the root system receives one set of stimuli 

 and the upper portion another, so that the interpretation is not as 

 simple as with animals. 



In the different stages of growth a creature may have different abil- 

 ity to withstand extremes. 



If the approach to unfavorable or noneffective conditions is gradual, 



