CONSTITUTION AND DEVELOPMENT OF TERMITES. 31 



in certaiu species of grasshoppers. Similar phenomena occur 

 in Psocidaj, Perlidse, «S:c. 



(2) The Embiidse, which, as will b6 seen later (Appendix II), 

 have been regarded as near allies of the Termitidse, though 

 they are nothing of the sort except in so far as they belong 

 to the same order, the Orthoptera (s. lat.), exhibit a sexual 

 dimorphism comparable with that subsisting between the 

 soldiers and other Termite forms, namely, a much greater 

 development of the mandibles in one sex than the other. 



As the marvellous effects produced by differences 

 in nutrition remain always indisputable, this would 

 lead us to believe that the intimate structure of 

 Termitidse may form, so to speak, a nidus specially 

 adapted for their manifestation.^ 



2. The great influence exercised on the genitalia by the 

 salivary secretion is a fact which finds its analogue in bees. And 

 inasmuch as these insects are very remote from Termitidse, and 

 are of independent phylogeny, it must be inferred that we 

 are in presence of a marvellous phenomenon of con- 

 vergence. 



3. If the aliment can exercise a profound influence on the 

 genital organs in forms so remote from each other as Termi- 

 tidse and bees, we may fairly suppose it to produce a direct 

 effect on these organs in many o'ther animals. And 

 this seems to me to form a serious argument in 

 favour of the possibility of inheriting acquired 

 characteristics. 



No light is thrown on the mode of development of the 



1 [In other words, the intimate structure of the protoplasm in other 

 species of Orthoptera already exhibits a tendency towards the production of 

 better developed mandibles in certain individuals (males). We may therefore 

 suppose that at one time the ancestors of Termitidse exhibited a much 

 greater development of the mandibles in one sex than the other. Similar 

 suppositions, and others which readily present themselves to one's mind 

 facilitate, in my opinion, the understanding as to how this character may 

 present itself in the soldiers without the invocation of direct inheritance. 

 (See the introduction to my memoir on " The Anatomy of the Thysanura.") 

 G. B. Grassi, December, 1S96.] 



