190 Annals Entomological Society of America [Vol. IV, 



Stbckard (11) describes the hatching of Aplopus mayeri as 

 follows: "When hatching the embryo's head and body come 

 forth from the egg first, the antennae are then pulled out, the 

 legs being the last parts liberated from the shell." The speci- 

 mens noted under E and F in the above table agree with Stock- 

 ard's observations on Aplopus, but both of these specimens 

 had their appendages caught in the amniotic membrane (Fig. 

 4). In a previous paper we (9) have already called attention 

 to the fact that dryness, at the time of hatching, has a marked 

 effect upon the emergence of the walking-stick from the egg. 

 With the addition of water which was added drop by drop to the 

 egg-shell, within which the above-mentioned specimens were 

 caught, these walking-sticks succeeded in freeing themselves. 



BIBLIOGRAPHY. 



1. Bourgeois. J., 1900. Sur un mode particulier de progression souterraine chez 



quelques larves d'Insectes. Bull. Soc. ent. Fr. LXVIV, pp. 261-2. 



2. Caudell, A. N., 1903. The Phasmidae, or Walking-Sticks of the United 



States. Proc. U. S. Nat. Mus. XXVI, No. 1335, p. 864. 



3. Kunckel d'Herculais, J., 1890. Mecanisme physiologiques de l'eclosion, 



des mues et de la metamorphose chez les Insectes Orthopteres de la famille 

 des Acridides. C. R. Acad. Sci. Paris, CX, pp. 657-9. 



4. , 1890. Du rule de l'air dans le mecanisme physiologique de l'eclo- 

 sion, des mues et de la metamorphose chez les Insectes Orthopteres de la 

 famille Acridides. Ibid. CX, pp. 807-9. 



5. Packard, A. S., 1877. 9th Ann. Rept. U. S. Geol. and Geographical Survey, 



pp. 630-4. 



6. • — , 1903. A Textbook of Entomology, pp. 585-6. 



7. Riley, C. V., 1877. 9th Ann. Rept. Noxious, Beneficial and other Insects of 



the State of M,,., pp. 89-90. 



8. Riley, C. V., Packard, A. S., and Thomas, C, 1878. 1st Ann. Rept. U. S. Ent. 



Com. 1877. Relating to the Rocky Mountain Locust. Wash. pp. 277-284. 



9. Severin, H. H. P., and Severin, H. C, 1910. The Effect of Moisture and Dry- 



ness on the Emergence from the Egg of the Walking-Stick, Diapheromera 

 femorata Say. Jour. Econ. Ent. Ill, No. 6, pp. 479-481. 

 10. , 1911. The Life-History of the Walking-Stick, Diapheromera fem- 

 orata Say. Jour. Econ. Ent. IV, No. 3. 

 11. Stockard, C.R., 1908. Habits, Reactions and Mating Instincts of the Walk- 

 ing-Stick. Aplopus mayeri. Publ. No. 103, Carnegie Inst., Wash., pp. 

 43-59 



EXPLANATION OF PLATE XIV. 

 All figures were drawn with a camera lucida. 

 Fig. 1. View of embryo after the operculum has been removed showing the 

 head and prothorax directly beneath. The pressure exerted by the cervical 

 ampulla, which joins the head dorsally to the prothorax, would be directly 

 against the operculum: h, head; p, prothorax; vi, vitelline membrane; c, compoun 1 

 eyes. 



Fig. 2. Longitudinal section through the head and thorax of the embryo, 

 showing the transverse folding of the thorax in a dorso-ventral direction; h, head; 

 p. prothorax; m, mesothorax; met, metathorax. 



Fig. 3. Walking-stick emerging from the egg, showing that the prothorax 

 is bent down at its union with the mesothorax: h, head; p, prothorax; m, meso- 

 thorax; op, operculum still adhering to the egg by means of the so-called "shell 

 membrane." 



Fig. 4. Walking-stick with its appendages caught within the egg-shell: 

 ha, "hilar area." 



