148 PROC. ENT. SOC. WASH., VOL. 22, NO. 6, JUNE, 1920 



Other interesting "abnormalities" are the soldiers with wing- 

 pads, a reversion to the ancestral winged condition. 



Of course, when their origin is explained as mutations, the 

 value of any of these castes to the colony life is not essential; 

 indeed, they even may be a hindrance, provided their presence 

 is "not entirely fatal to the community," (Morgan, 1903). 



Imms (1919) states that the origin of the castes in termites may 

 be explained by Mendelian inheritance. 



It will readily be seen that my studies of the biology and breed- 

 ing habits of the three types of reproductive forms are as yet in- 

 complete. The results of the breeding and especially the cross- 

 breeding experiments are, in general, unsatisfactory. Neverthe- 

 less, it is believed that, while these preliminary results of breeding 

 and attempts at cross-breeding are not conclusive, they show the 

 trend that future experiments should follow. 



Future biological and histological studies should in time solve 

 the problems. 



Some of the especially important problems needing elucidation 

 or confirmation are: 



(1) More exact proof that the second and third reproductive forms breed 

 true to type. 



(2) The nature of the progeny of the "intermediate" reproductive forms. 



(3) The methods of colonization of the second and third reproductive forms 

 and whether they can survive without workers. 



(4) The exact number of molts undergone by each caste and the accom- 

 panying external and internal changes that occur at the time of the molt 

 or between molts, as the increase in the number of antennal joints, etc. (The 

 growth of the latter, however, apparently has no relationship to the time 

 and number of molts that take place.) 



(5) Studies of the third reproductive form in the more primitive termites, 

 as Termopsis, Neotermes, etc. 



(6) Proof of the apparent absence of the third form reproductive type in 

 the higher, more specialized termites (of the family Termitidae Bks.) and also 

 that of the second form reproductive type in some genera of the higher ter- 

 mites (as in species of Nasutitermes Bks.). 



LITERATURE CITED. 



1893. Grassi, B., and Sandias, A. Costituzione e Sviluppo della societa dei 

 termitidi, etc. Dagli Atti dell'Acad. Gioenia di sci. nat. in Cata- 

 nia, Vol. Vie ser. 4 Catania. 



1893. Joutel, L. H. Some notes on the ravages of the white ant (Termes 

 flavipes}. Jour. N. Y. Ent. Soc., Vol. 1, No. 2, pp. 89-90, June. 



1901. Schwarz, E. A. Proc. Ent. Soc. Wash., Vol. 4, No. 4, p. 347 (Jan., 1889). 



1902. Schaeffer, C. Jour. N. Y. Ent. Soc., Vol. 10, No. 4, p. 251, December. 

 1904. Maeterlinck, M. The life of the bee. New York. 



