476 MAUD D. HAVILAND 
the death of the aphid, and post-embryonic development is 
internal. 
4. A trophic membrane of hypertrophied cells is formed 
round the embryo. 
5. The larva is, at first, hypermetamorphic; and exhibits 
sreater development of the chitinous cuticle than is usual 
in endoparasites ; but in the succeeding stages it approximates 
more closely to the general hymenopterous type. 
6. The development of the Aphidius is arrested at 
a certain point, and metamorphosis does not take place. 
7. The Cynipid, when ready to pupate, makes its way out 
of the Aphidius, whose remains it devours, and undergoes 
metamorphosis within the cocoon previously woven by the 
latter in the skin of the aphid. 
8. These forms differ in certain particulars from the ento- 
mophagous Cynipidae previously deseribed, and the chief 
differences are discussed. 
9. Comparison is also made of the larvae of other Hymeno- 
ptera Parasitica, particularly of Perilampus. 
10. Certain problems of metabolism are pointed out, and it 
is suggested that respiration may be partly rectal. 
11. These Cynipidae are economically injurious as they 
check the Aphidius in its destruction of plant-lice; but 
there is high mortality among the larvae owing to secondary 
parasitization of the Braconid by other hyperparasites. 
BIBLIOGRAPHY. 
1. Adler, H. (1881).—“‘ Ueber den Generationswechsel der Hichen-Gall- 
wespen ”’, ‘ Zeit. wiss. Zool.’, Bd. xxxv, pp. 151-246, Taf. x—xii. 
2. Bouché (1834).—‘ Naturgeschichte der Insecten.’ 
3. Cameron, Peter (1890).—* A Monograph of the British Phytophagous 
Hymenoptera ’, Ray Society’s Publications, vol. ii. 
4. Embleton, Alice (1904).—“ On the Anatomy and Development of 
Comys infelix, Embleton”’, ‘Trans. Linn, Soc.’, vol. ix, pt. 5, 
p. 231. Pts. 11-12. 
5. Ganin, M. (1869).—-‘‘ Beitrige zur Kenntniss der Entwickelungs- 
geschichte bei den Insecten ”’, ‘ Zeit. wiss. Zool.’, Bd. xix, pp. 381- 
448, Taf. xxx-xxxiil. 
