50 Mr. S. S. Saunders's Description of 



metamorphoses of the Polistes* while offering a remarkable con- 

 trast to the tardy development of the larvae of other Strepsip- 

 terous parasites, which, like Stylops, Halktophagus, and those 

 affecting the Hijlcei, are associated with bees long retaining their 

 immature condition, and enjoying comparatively but a brief exist- 

 ence after quitting their cells in the imago state. 



But, on the other hand, it is well known that among wasps, 

 neuters alone are produced up to a certain period, upon which the 

 duty subsequently devolves of preparing the cells set apart for 

 females ; and the Xenos being essentially dependent upon the 

 hybernation of the latter, the female parasite of the preceding 

 year must either await the occasion when the cells of the female 

 wasps are so prepared for the reception of ova, or otherwise, 

 transmitting her posterity to these females through the inter- 

 medium of neuters in the first instance, the Xenos would thus 

 prove to be double-brooded, a circumstance which could scarcely 

 have escaped the observation of Dr. Siebold ; although indeed the 

 time at which the first pupae of the males are stated to show 

 themselves, (preceded by the appearance of the young hexapods as 

 already recited, such hexapods being also necessarily present after 

 the formation of the female cells,) would seem to warrant such a 

 conclusion. ~\ 



It has also to be considered that bees, whose vital energies have 

 become impaired, and internal economy disorganized, by the sus- 

 tenance and accommodation afforded to Strepsipterous parasites, 

 are generally believed to be sterile and impotent ; as long since 

 suggested by Kirby, and confirmed by subsequent observers, par- 

 ticularly by Mr. Newport, when describing the condition of the 

 ovaries in his stylopized specimen of Andrena Trimmerana. It may 

 then be asked, does this law apply with equal force and effect to 

 the parasite-bearing Polistes? If such be the fact, the hyber- 

 nating wasps so attacked, not being themselves capable of forming 

 new colonies, the hexapod brood of the Xenos, like that of Stylojis, 

 must be transferred by adventitious means to the larva cells of 

 some other constructor ; nor does it seem probable that under 

 such circumstances the unproductive hybernating Polistes should 

 survive to an advanced period, the prevailing efficacy and sustain- 

 ing power of instinct being already withdrawn. 



It does not, however, appear to be specifically averred whether 

 the hexapods and pupae, which Dr. Siebold noticed so early in 



* Saint Fargeau, Suites a Buffon — Hymenopteres, (Histoire des Polistides,) 

 tome i. p. 475, et sea. 



t Jurine informs us that his males of Xenos were produced from the Polistes, 

 on the 27th and 28th July, and 1st of August. 



