250 B. GRASSI AND A. SANDIAS. 
on another species of Calotermes, and these, as will be seen 
later, are in entire agreement with our observations on the 
European species. 
Nevertheless, as I have already mentioned, the study of 
Termitide in general is as yet very incomplete ; and although 
books of travel certainly abound in notices of these interesting 
insects, they mostly deal with detached and imperfect obser- 
vations. 
I have repeated Lespés’ investigations on Termes luci- 
fugus with particular reference to the so-called ‘“ nymph of 
the second form” which that distinguished naturalist de- 
scribed. 
He attributed to it an entirely different significance from 
that which it really possesses, owing mainly to the circum- 
stance that his period of study was confined to about nine 
months—from November, 1855, to August, 1856. But how 
difficult the elucidation of the true function of this nymph of 
the second form has been the reader will gather from the 
pages of this memoir; and I may state at once that it has 
necessitated the removal of many hundred cubic metres of 
earth and the cutting up of hundreds of trees, a task that has 
had to be carried out little by little, and has consequently 
demanded no small amount of patience. 
I am indebted to a small but fortunate discovery for the 
most interesting observations on Calotermes flavicollis, 
which I have to relate in the present work. 
If from three to twenty Calotermes of different ages are 
placed in a glass tube three to eight centimetres long (Pl. 19, 
fig. 11), closed with a cork and kept warm—for example, in the 
waistcoat pocket, unless in summer-time, they continue to live 
and constitute a family, or better, an independent colony ; they 
rear a fresh king and queen,’ if orphaned, and they rear soldiers, 
1 [The statements made on the sexual forms of Termitide will be more 
clearly understood if anticipated by a summary and definition of the terms 
employed in the course of the work. Sexual or royal forms are of two 
kinds, true and neoteinic. The true royal forms are imagos, or 
perfect insects, which acquire a complete development of the wings and 
