530 CAROLINE BURLING THOMPSON 



5. Three additional variations or types are of occasional oc- 

 currence. These are: second and third forms with very small 

 wing vestiges and soldiers with wing vestiges. There is no cor- 

 relation between the presence of wing vestiges and fertility, 

 but brain size and fertility are invariably correlated. 



6. A plate-hke non-functional frontal gland, without fontanel, 

 is present in first-form n>Tiiphs and adults. 



7. Vestiges of the lateral ocelh are found in all the castes, 

 except, possibly the third form. 



8. There is great variability in all organs, and even in the de- 

 gree of infertility of some female soldiers. 



9. Termopsis is considered a very primitive genus, on account 

 of its many ancestral characters and its close resemblance to the 

 even more primitive genus Archotermopsis. 



10. The castes of termites are regarded as segregants, arising by 

 mendehan inheritance from a heterozygous parent form. 



Wellesley, Massachusetts 

 July, 1921 



BIBLIOGRAPHY 



Banks, N., and Snyder, T. E. 1919 Revision of Nearctic termites with notes 



on biology and geographic distribution. U. S. National Museum, Bull. 



108. 

 Boring, Alice M., AND Pearl, Raymond 1918 Sex studies. XI. Hermaphro- 

 dite birds. Jour. Exp. Zool., vol. 25. 

 BuGNiON, E. 1912 Observations sur les termites. Differentiation des Castes. 



Comp. Rend. Soc. Biol. Paris, I, T. 72. 

 CoMSTOCK, J. H. 1918 The wings of insects. Ithaca, New York. 

 Feytattd, J. 1912 Contribution a l'6tude du termite lucifuge. Arch, d'anat. 



micros., T. 13. 

 Fuller, Clattde 1920 Studies on the post-embryonic development of the 



antennae of termites. Annals Natal Museum, vol. 4. 

 Grassi, B., and Sandias, A. 1893-94 Costituzione e sviluppo 'della society 



dei Termitidae. Atti Acad. Gioenia di sci. nat., Catania. 

 Heath, Harold 1903 The habits of California termites. Biol. Bull., vol. 4. 

 Holmgren, N. 1909 Termitenstudien 1. Anat. K. Svenska Vetensk. Akad. 



Handl., Bd.44. 



1911 Termitenstudien 2. System. K. Svenska Vetensk. Akad. 



Handl., Bd. 46. 

 Imms, A. D. 1919 On the structure and biology of Archotermopsis, together 



with descriptions of new species of intestinal Protozoa, and general 



observations on the Isoptera. Phil. Trans. Royal Soc. London, 



Series B. vol. 209. 



