14 B. GRASSI AND A. SANDIAS. 



These facts have been confirmed on very many occasions. 



3. Furthermore, a nest was made up of three large larvae 

 only ; after a fortnight one of these exhibited pigmented 

 eyes, and was therefore in process of becoming a substitute 

 form. 



3. The formation of substitutes may take place at any 

 time of the year, and is never delayed for more than a fortnight 

 if the tube is carried in the waistcoat pocket. 



4. If a nest containing growing examples is furnished with 

 adults ready to fly, or with the wings shed in the act of capture, 

 the formation of royal substitutes takes place as usual, while 

 the perfect insects bore through the cork and escape in search 

 of fresh quarters. This confirms the observation that Calo- 

 termes does not make use of perfect insects capable of flight 

 as substitute forms ; and the reason of this is certainly to be 

 found in that prepotent instinct towards quitting the nest 

 which arises in all Termitidse as soon as they become fully 

 coloured imagos. 



5. If a nest is formed only of examples with not more than 

 twelve antenual joints, substitute forms are not developed 

 within the usual period. But if a few small-headed larvae, with 

 from fourteen to sixteen antennal joints, are included, they are 

 promptly transformed into larvse of royal substitutes. 



6. A colony of about two hundred Calotermites is collected 

 and separated into some fifteen nests, the royal pair being 

 purposely killed. Every nest will furnish two, three, or four 

 substitute forms. 



Another colony of equal size is collected and put into a 

 single glass jar after destruction of the royal pair; it will 

 form from four to six substitutes. 



The same number of Calotermites will therefore produce a 

 very large or a very small quantity of substitute forms accord- 

 ing to circumstances. 



These simple experiments at once suggest that the ordinary 

 members of the colony are capable of development into these 

 forms ; and further justification for this view is found in the 

 fact that specimens in difl'erent stages of development (without. 



