16 INSECTS IXJUKIOUS TO FORESTS. 
part of the coal measures (Allegheny, North America), but the 
youngest "Protoblattoiden" occur in the lower Permian formation 
of Europe. Holmgren considers the termites to be in a distinct 
order, the Isoptera. 
The order Isoptera, according to Holmgren (1911), a is divided into 
three families, the Protermitidse, the Mesotermitidse, and the Meta- 
termitidse. All of these families are represented in North America, 
and while this paper is restricted to a discussion of species of the 
genus Leucotermes Silvestri, subfamily Leucotermitina? Holmgren, 
family Mesotermitidse Holmgren, a species in the genus Termopsis 
Heer, subfamily Termopsinee Holmgren, family Protermitidas Holm- 
gren, is briefly mentioned. Thus it will be seen that the species 
under observation occupy a middle position between the highest 
and the lowest genera in the systematic classification of termites. 
HISTORICAL. 
According to Desneux, Smeathman's marvelous descriptions in 
Some Account of the Termites Which Are Found in Africa and Other 
Hot Climates (London, 1781) are the real basis of scientific re- 
searches on the biology of termites. 5 Hagen c gives a resume of the 
researches on termites up to 1860. Drummond's Tropical Africa 
(London, 1889), in chapter 6, gives an interesting account of " white 
ants." Froggatt, in Australian Ternritidae/ gives a resume of the 
studies of various workers on termites. Saville-Kent, in Chapter 
III of the Naturalist in Australia (London, 1897), describes the 
habits of termites in the Tropics; Smeathman, Drummond, and 
Saville-Kent in their popular accounts of termites stimulated interest 
in the habits of these insects and led to scientific researches. Grassi 
and Sandias, 6 in their classical work, have outlined the results of 
the more important biological researches. Sharp / gives an excellent 
« Holmgren, N. Termitenstudien 2. Systematik der Termiten. K. Svenska 
Vetensk. Akad. Handl.. Bd. 46, No.6, pp. 86, Taf. 1-6, Uppsala & Stockholm, 1911. 
Ordnung Isoptera, p. 10-11. 
& Smeathman, H. Some account of the termites, which are found in Africa and 
other hot climates. In Philos. Trans. London, v. 71. p. 139-192, 3 pis., 1781. (Smeath- 
man's observations were afterwards confirmed by Savage in 1850 and the late G. D. 
Haviland.) 
c Hagen, H. A. Monographie der termiten. Linnaea Entomologica, v. 10, 1855, 
p. 1-144, 270-325; v. 12, 1858, p. 1-342, pi. 3; v. 14, 1860. p. 73-128. 
d Froggatt, W. W. Australian Termitidae, Part I. Proc. Linn. Soc. N. S. Wales, 
v. 10, ser. 2, p. 415-438, July 31, 1895. Distribution, p. 416^26. 
e Grassi, B., and Sandias, A. The constitution and development of the society of 
termites; observations on their habits; with appendices on the parasitic protozoa of 
Termitidse and on the Embiidse translated by F. H. Blandford. Quart. Jour. 
Micros. Sci. [London], v. 39, pt, 3, n. s., p. 245-322, fold. pi. 16-20, November, 1896, 
and v. 40, pt, 1, p. 1-75, April, 1897. 
/Sharp, D. Cambridge Nat. Hist,, vol. 5, Insects, Pt. 1. chap. 16. p. 356-390, Lon- 
don, 1901. 
