28 B. GRASSI AND A. SANDIAS. 



goal, because they remain unchanged in some nests for months 

 together. The pigmentation of the eyes found in some of 

 these nymph-soldiers is curious but intelligible. 



Similar experiments were made on natural nests in trees by 

 removal of a large number of soldiers, and after some time a 

 few nymph-soldiers were found in them. 



I was led by this to suspect that such forms may at times 

 be normally found in intact nests, and by paying particular 

 attention to the origin of the large soldiers I actually found 

 that normal nests in which the soldiers originate from larvae 

 with wing-buds, or nymphs, are not rare; this phenomenon has 

 escaped the most accurate investigators, including Fritz Miiller, 

 on account of the reduction of the wing-rudiments, which 

 perhaps disappear completely in the case of larvae.* 



The following fact shows that these phenomena hold good 

 equally for Termes. 



In a small nest of Termes lucifugus kept in a glass jar 

 I obtained a nymph-soldier which had almost exactly the 

 thorax of a nymph of the second form, and the head of a soldier. 

 At the time of formation the nest contained a certain number 

 of perfect insects, many workers, a few soldiers, and some 

 undifferentiated larvae. This nymph-soldier was found in it 

 six. months later, together with a number of workers, an 

 ordinary soldier, and a nymph of the second form. Death 

 had evidently claimed many victims during the six months 

 that the nest lasted. 



I have met with similar nymph-soldiers on other occa- 

 sions. All these observations are sufficient to show that the 

 casts of workers and soldiers denote merely a paranomalous 

 development of individuals capable of becoming perfect in- 

 sects. 



3. Further evidence is afforded by the fact that the newly born 

 larvae are relatively alike inter se, — relatively only, because 

 they are not all identical in bulk. This was observed by taking 

 Calotermites in the act of hatching (they emerge at one pole 

 of the egg) and comparing them after preservation by a uni- 

 form method. 



