The effect of cold exposure, epinephrine injection, and a combined cold-epinephrine treatment on the eosinophil level of the turtle, Pseudemys elegans, was studied in order to ascertain information regarding the sensitivity of the endocrine and nervous systems of a poikilotherm to stresses. A low temperature environment produced an eosinopenia; the average fall was 34.8% below the control level. Epinephrine injection resulted in an eosinophilia; the average rise was 37.4% above the control level. Combined treatment with cold and epinephrine resulted in an eosinopenia; the average fall was 32.8% below the control level. It is concluded that the turtle shows an endocrine response to cold stress.
