1 62 HAROLD HEATH. 



same period many naturally established nests were located, both 

 at Pacific Grove and about Stanford University, and served to 

 check up results. 



In some instances the death of one or both of the royal pair, 

 whether free or in captivity, took place before three years had 

 elapsed ; but in certain cases this was undoubtedly due to an 

 unfavorable habitat occasioned by excessive drought or moisture 

 or more often to the ravages of Termes lucifugus. Beyond this 

 time their destruction could not so readily be traced to adverse 

 conditions, and may rather be due to exhaustion produced by 

 the arduous duties attendant upon the development of a healthy 

 flourishing progeny. A careful examination showed that at the 

 end of four and one half years the greater number of the kings 

 and queens had died, not over 10 per cent, remaining. After 

 five years I was able to find only six colonies, out of two hun- 

 dred and thirteen, in which royal forms were present, and but two 

 of these contained both king and queen. In a two-quart fruit 

 jar, which was hermetically sealed and opened only once or twice 

 a year to add water and wood and to remove portions of the con- 

 tinually increasing walls and barricades, I kept a royal pair a 

 few days over five years and eight months. At this time the 

 male died and the queen followed about three months later. 

 From the foregoing it appears that the average life of the royal 

 pair is of at least one year duration in their immature condition, 

 and between four and five after leaving the nest. And further, 

 the life of the male is of practically the same length as that of the 

 female. 



To determine the longevity of the workers and soldiers I have 

 in several cases removed from a large colony one or two workers 

 and soldiers which had recently undergone their final molt along 

 with many smaller forms, and have thus been able to distinguish 

 these larger insects from their fellows and to determine their span 

 of life. And again, owing to some slight deformity or some 

 mutilation it has been possible to recognize others in a normally 

 developing colony and to trace their history for years at a time. 

 Also I have taken large communities, headed by true orcomple- 

 mental royal forms, and by removing the young as fast as they 

 appeared, have been able to determine the approximate length of 

 life of all the individuals. From these observations it results 



