334 Mr. Newport on the Natural History 
Xenos sphecidarum, and which, like previous observers, he then thought were 
parasites, but he also discovered and described the ova in which they were pro- 
duced within the body of the Xenos. More recently * he has shown that these 
are the ova and the young of Xenos; and that the female Strepsiptera are blind, 
apodal, larviform insects, that never leave the bodies of the Hymenoptera in 
which they have lived as parasites, but remain with only the cephalo-thoracic 
portion of their bodies exposed, and there produce their young and die. The 
males escape, and fly abroad as winged insects, and impregnate the females 
while these are still within the Hymenoptera in which they have been nou- 
rished. The larvae, consequently, as in Hippobosca, Aphis, and some other of 
the inferior parasitic tribes, are hatched within the bodies of their parents, 
and pass out, to the surface of that of the wasp or bee, through the vulva, 
which is situated in her cephalo-thorax on the ventral surface. The larvae 
thus produced (Tas. XIV. fig. 21), like those of Meloé, are at first distinctly 
hexapod, and capable of locomotion ; they cling fast to the hairs on the body 
of the wasp or bee (Tas. XIV. fig. 22) in which they have been hatched, and 
are transported by the insect to its nest, where they remain, as I have already 
shown is the case with Meloë. The larvee of Strepsiptera penetrate the body 
of the young larva of the hymenopterous insect in its cell, and locating them- 
selves in it, shed their skins, lose their legs, become completely apodal, and 
there feed on its substance, through the whole period of their nutrition, as 
internal parasites. These facts have been fully exemplified by Dr. Siebold1. 
. The attention of naturalists was drawn to them quickly after their publication, 
in France, by MM. Milne Edwards ft and Guerin Meneville §, and in this 
country by myself ||, my friend Mr. Spence baving kindly apprised me of 
them. Since then, some of them have been confirmed by Mr. Smith's €| and 
my own observations. I have detailed Dr. Siebold's discoveries here, in their 
natural sequence, in order, first, more fully to confirm them, and to add some- 
thing to the description and history of these singular insects; and next, to be 
enabled more readily to compare the anatomy and habits of the larvze with- 
those of Meloé. 
* Wiegmann's Archiv, 1843. T Ibid. p. 137 et seq. 
t Ann. des Sci. Nat. 1844. $ Rev. Zool., March 1844, p. 111-118. 
il Anniversary Address Ent. Soc. Lond., Feb. 1845, pp. 19, 20. 
*| Zoologist, No. xxii., Sept. 1845, p. 1092. 
