Ernest Warren 
347 
(4) The correlation of the means of any two castes in a nest of a population 
of colonies is of very considerable magnitude, being about '9. In other words 
when, for example, the mean of one caste is above the average, then the mean 
of any other caste in the nest is correspondingly high. Leaving out the effect 
of inheritance, this correlation could be accounted for by the fact that similar 
environmental influences would act on all the members of a nest. 
(5) The standard deviations of the means of different castes in a population of 
colonies are considerable; and there is little doubt that the varying environment 
of each colony is largely responsible for the great fluctuations in the means. 
(6) The correlation of the coefficients of variation of any two castes in a 
population of nests is either moderate or nil, in other words the variability of one 
caste is in some instances not appreciably correlated with the variability of any 
other caste in the nest. Owing to the fact that all the castes spring from the 
same parentage, we might have anticipated that a fairly high correlation would 
exist. We have therefore evidence that a similar environment can have a varying 
influence on the variabilities of the different castes. 
A comparison of these results with those obtained from other social insects 
would be of much interest, and would throw additional light on the significance, 
or otherwise, of some of the observations made in this paper. 
44—2 
