THE CLASS OV INSECTS. 



pseudova, must depend upon a something impressed upon the 

 constitution of the parent before it was brought forth by its 

 viviparous progenetrix." (Huxley.) 



Siebold has also shown that the wt ova of the Queen-bee pro- 

 duces females or males, according as they are fecundated or 

 not. The fecundated ovum produces a queen or a neuter 

 according to the food of the larva and the other conditions to 

 which it is subjected ; the unfecundated ovum produces a 

 drone." This is analogous to the agamic reproduction of 

 Aphis, and demonstrates still more clearly the impossi- 

 bility of drawing airy absolute line of demarcation histologi- 

 cally between ova and buds." 



This process of reproduction is not known in the Myriapods. 

 It occurs among the mites (A<-<trin<i)* and occurs in isolated 

 genera of Hemiptera (Aphis, Chermex, Lvcunium, and Aspidi- 

 otitH according to Gerstaecker). 



Among Lepidoptera the .Silk-moth sometimes lays fertile 

 eggs without previous sexual union. This very rarely hap- 

 pens, for M. Jourdain found that, out of about 58,000 eggs 

 laid by unimpregnated silk-moths, many passed through their 

 early embryonic stages, showing that they were capable of 

 self-development, but only twenty-nine out of the whole 

 number produced caterpillars. (Darwin.) Several other moths * 

 have been found to lay fertile eggs without previous sexual 

 union, and among Ilymenoptera, Nematus -centr'n-usus, Cynijix, 

 Neuroterus, perhaps Apophyllus (according to Gerstaecker), 

 and Cynips sponyijica (according to Walsh, Proceedings of 



* We give a list from Gerstaecker (Bronn's ClassenundOrdnangend.es Thier- 

 reichs) of all the known cases of agamic reproduction in this suborder, with the 

 number of times the phenomenon has been observed, and the names of the ob- 

 servers. 



Giistropncha quercus, once (Plieninger). 



Liptiris tlinpiir, once (Carlier). 



" Kfffffrmuth" (1 Liparls disptir], (Tardy, 



Westwood). 



I.i/Kiris ochropoda, once (Popoff). 

 Orgyia pudibunda, once (Werneburg). 

 Fvi/che apiforniis, once (Rossi). 



" helix (Siebold). 

 Solenoblu. liclienella (Siebold). 



triquetrella (Siebold). 

 Bomlnjx mori, several times. 



Sphinx lif/ustri, once (Treviranus). 

 Smerinthus populi, four times (Nord- 



mann). 



Smerinthus ocellntus, once (Johnston). 

 Euprepla caja, live times (Brown, etc.). 



" villica, once (Stowell). 

 Tclert Polyphemus, twice (Curtis). 

 Gastropacha pint, three times (Scopoli, 



etc). 



Gastropacha ijuernfolia, once (Easier). 

 " potatoria, once (Burmeis- 



ter). 



The subject has been also discussed by Siebold in his work entitled, A true Par- 

 thenogenesis in Lepidoptera and Bees; by Owen, in his "Parthenogenesis," and 

 Ijy Sir J. Ltibbock in the Philosophical Transactions, London, vol. 147, pt. 1. 



