Experimental cold modification of cranio‐facial morphology

A possible relationship between cranio‐facial form and growth under cold stress was investigated through a control group (N=17)—experimental group (N=14) comparison. Two groups of young rats were exposed to 90 days of 22°C and 5°C temperatures respectively. Methods of analysis included measurement of overall bodily dimensions as well as detailed examination of the cleaned, dried skulls and femora. Statistical comparison of the cold and non‐cold grown rats showed a number of highly significant mean differences; particularly a narrower nose, rounder neurocranium, and shorter femur was seen in the cold stressed animals. Human anatomical homologs were briefly noted as were their possible genetic and ontogenetic causes.