32 B. GRASSI AND A. SANDIAS. 



workers, soldiers, and neoteinic forms, either by the compari- 

 son instituted by Darwin or by the existence of worker bees 

 capable of oviposition.^ 



I regard it as possible that the characteristics of these three 

 classes of forms may be suddenly manifested, because, as I have 

 previously suggested, the latent tendencies may be pre-existent 

 in the as yet undifferentiated Termite larvse. 



4. Since the development of workers, soldiers, and neo- 

 teinic forms is arrested, as many of their characters show, 

 and since the metamorphosis of Termitidae is incomplete, the 

 development of castes in this family is entirely different from 

 that which occurs in bees, ants, &c. 



Further, the fact remains that the workers, soldiers, and 

 neoteinic forms on the one part and the perfect insects on the 

 other part are not separated by that enormous difference of 

 instincts which is manifested between the queen and worker 

 bees. On the contrary, the instincts of the former group of 

 forms are possessed generally by the other members of the 

 Termite colony. 



5. In the desire to estimate the importance which attaches 

 to the facts disclosed of my investigations on TermitidEe, I 

 propose to begin by the consideration of a preliminary question. 

 In earlier geological periods the Termitidae were represented 

 in Europe by numerous species, which are now reduced to 

 two, and confined to S. Europe, whilst a large number still 

 exist in the tropical and subtropical zones. 



This and other facts already discussed indicate that the 

 different European distribution of Termitidae at other periods 

 was probably dependent on the warmer climate which then 

 prevailed over this part of the world. 



These considerations, together with the fact that our termite 



1 [Of late I have changed my mind, having had occasion to meet with a 

 nymph-soldier (vide p. 14) of Termes lucifugus with well-developed 

 ovarian tubes, and return to the supposition that the phenomena of inheritance 

 in the sterile casts of Termitidae (workers and soldiers) can be interpreted 

 as I have pointed out in the introduction for the bees, i. e. by the exceptional 

 existence of workers and soldiers capable of oviposition. — G. B. Grassi, 

 December, 1896.] 



