100 Annals Entomological Society of America [Vol. XIV, 
sary to make a detailed study of the head, neck plates, thoracic 
sclerites and appendages, and the terminal abdominal structures, 
if the results are to be based upon a firm foundation, since any 
view based upon the study of the wings alone, and not sup- 
ported by the evidence drawn from the study of other parts 
of the body as well, can be accepted only with reservation. 
So far as the study of the origin of insects and their immediate 
relatives is concerned, I have found the head structures, and 
the mandibles in particular, to be of the greatest value; and the 
study of the head structures in the various orders of insects 
promises to be of equal importance in determining the inter- 
relationships of insects themselves. 
BIBLIOGRAPHY. 
Berlese—Gli Insetti—Milan, 1909. 
Boerner—Mouthparts of Opisthogoneata—Sitz. Ber. Gesell. Naturf. Fr. Berlin, 
1903, p. 58. 
Chatin—Morphol. Comp. des Pieces Maxillaires, etc., chez les Insectes Broyeurs, 
Toulouse, 1884; and La Machoire des Insectes—Paris, 1897. 
Comstock and Kochi—Head of Insects—Amer. Nat., 26, 1902, p. 13. 
Crampton—Maxillae of Orthoptera—Psyche, 23, 1916, p. 88; Head of Insects— 
Ent. News, 28, 1917; p. 398, and Ann. Ent. Soc. America, 10, 1917, p. 337; 
Neck of Insects—Ann. Ent. Soc. America, 10, 1917, p. 187; Head of Trichoptera 
and Lepidoptera—Psyche, 27, 1920, p. 23; Ancestry of Insectan Orders— 
Trans. Ent. Soc. London, 1919, p. 98, Ent. News, 30, 1919, p. 42, and Psyche, 
27, 1920, p. 116; Evolution and Interpretation of Parts of Mandible in Insecta 
and Allied Arthropods—Jour. N. Y. Ent. Soc., 1921; of Superlingulae—Psyche, 
1921; of Maxillae—Proc. Ent. Soc. Washington, 1921. 
Folsom—Mouthparts of Collembola—Bull. Mus. Comp. Zool., Harvard, 36, No. 5, 
1900, p. 87. 
Forbes—Structure of Caterpillars—Ann. Ent. Soc. America, 3, 1910, p. 94. 
Fracker—Lepidopterous Larvae—Ill. Biol. Monogr. 2, No. 1, 1915, p. 5. 
Heymons—Various embryological papers; Embryology of Hemiptera—Nova. 
Acta. Abh. K. L. C. Deutschen Akad. Naturf. 74, No. 3, p. 353. 
Holmgren—Termitenstudien—Kgl. Sv. Vetskakad. Handl., 44, No. 3, p. 3. 
Hosford—Head of Insects—Kans. Univ. Sci. Bull. 8, 1913, p. 65. 
Janet—Const. Morphol. de la Tete del’Insecte, Paris, 1899. 
Kellogg—Mouthparts of Insects—Amer. Nat., 26, 1902, p. 683; Mouthparts of 
Lepidoptera—Amer. Nat., 5, 1895, p. 546; Mouthparts of Diptera—Psyche, 8, 
1899, p. 308, 327, 346, 355, 363. 
MacGillivray—Head of Sawfly Larvae—44th Ann. Rept. Ent. Soc. Ontario, 1913, 
p. 54. 
Mangan—Mouthparts of Blattidae—Proc. Roy. Irish Acad. 27, 1908, p. 1. 
Packard—Head of Insects—8rd. Rpt. U. S. Ent. Comm., 1882, p. 304; Entomology, 
1898. 
Peterson—Head of Diptera—I11. Biol. Monographs, 3, 1916, No. 2. 
Riley—Embryology of Head of Blatta—Amer. Nat., 38, 1904, p. 777. 
Smith—Mouthparts of Insects—Amer. Phil. Soc., 19, 1896, p. 175; Mouthparts of 
Diptera—Trans. Amer. Ent. Soc. 17, 1890, p. 319. 
Verhoeff—Head of Insects—Nova. Acta. Abh. K. L. C. Deuts. Akad. Naturf. 84, 
1904, p. 3. 
Waterhouse—Mouthparts of Insects, London, 1895. 
Wesche—Papers on Mouthparts of Diptera in Jour. Roy. Micr. Soc., 1902, p. 412; 
Ibid., 1909, p. 1; Ibid, 1904, p. 28; Trans. Linn. Soc. London, 9, 1906, p. 339; 
and Jour. Queck. Micr. Club, 1908, p. 283. 
Yuasa—Head of Orthoptera and Dermaptera—Jour. Morphol., 33, 1920, p. 251. 
