MISCELLANEOUS NOTES. 531 



members; the other, the "substitute forms" are developed on an 

 emergency to supply their loss. la Sicily, according to Grassi, the "winged 

 imagos are entirely lost after swarming, and never give rise to fresh 

 societies ; but there is evidence t*at this remarkable example of natural 

 wastefulness is not constantly exhibited in France. According to M rlatt, the 

 closely-allied Termes flavipes of North America is known to reproduce by 

 means of complementary forms alone. 



Grassi holds that the caste-modifications are caused by variation in 

 nutriment, and records a series of minute observations on the rather 

 repulsive feeding-h bits of these insicts, made chiefly by his coadjutor 

 Dr. Sandias. The staple food is wood, pas-sed and repassed through the 

 alimentary canal of several individuals ; the society tolerates no waste, 

 and everything of nutritive value, cast skins and dead bodies aiike, is greedily 

 devoured. 



Newly-born larvae and forms destined for sexual maturity are fed upon the 

 saliva of their comrades, the largest amount being given to those which are 

 becoming neoceinic ; within forty-eight hours after its administration they 

 become altered, acquiring ocular pigmentation and a translucent white 

 appearance. 



It is therefore contended that sexual development is directly stimulated by 

 the saliva taken as food ; but a disturbing factor has had to be eliminated. 

 The aliment try canal of most Termites teems with protozoa, which bring 

 about the dilatation of a csecal ampulla so as to fill the greater part of 

 the abdomen. These protozoa disappear under the influence of a salivary 

 diet, and the question has arisen whether the resulting diminution in size 

 of the ampul* may canse the gonads 10 ripen. Grassi answers this in the 

 negative. All Temiite* lose their parasitic protozoa at the time of moult- 

 ing, an I by taking advantage of this circumstance he has h en able to keep 

 co'onies alive for a month or more entirely frea from protozoa. A few 

 examples only in these colonies became neoteinic ; and it is therefore clear 

 that the saliva is one, if not the only, necessary factor in bringing about sexual 

 maturity. 



No light has been thrown on the causes which, in Termes, lead to the 

 differentiation of the soldier from the worker ; but it may be reasonably 

 inferred that they are also due to differences in nutrition. 



As already indicated, the re- ults of this research are directly opposed to 

 the hypothesis that special ova or special sets of ' determinants " exist for the 

 various castes iu Termttidce. It is not necessary here to < weil upon this , oint 

 which, it may he recolle.-ted,h s been dealt with conclusively by VI r. Herbert 

 Spencer in his controversy with Prof. Weisniann [Contemporary Review, 

 October, 1894). 



The means by which the special characters of the sterile castes are inherited 

 is a matter which has caused Prof. Grassi some trouble. In the original 

 24 



