119 



common in England, being two inches or more in diameter. According 

 to Mr. Walsh's observations the males are only obtained from those 

 galls which develop flies early in the season, two months before the 

 great autumnal brood appears, the latter all being invariably of the 

 female sex. Following up this we may hope this year to obtain males 

 of Cynips Ligiiicola. " 



It will be seen from the instances cited that Parthenogenesis cer- 

 tainly occurred more generally in the insect world than the few at 

 present discovered examples led us to suppose. Von Siebold was of 

 opinion that it occurs in accordance with determinate laws which had 

 hitherto entirely eluded our observation. 



In Nature definite objects were probably obtained by it which we 

 could only comprehend when we should have learnt to know the life 

 and actions of insects in general more exactly than was at present the 

 case. 



Before commencing the subject of sexual generation, a few obser- 

 vations were necessary on Hermaphroditism among insects. It was no 

 doubt well known that perfect Hermaphrodites amongst animals were 

 found only in the tape worm, many Annelida (for example, the leech 

 and the earth worm), and the majority of the Mollusca. In insects, 

 according to present observations, Hermaphroditism was but one- 

 sided, the left side generally exhibiting female forms and organs and 

 the opposite side male organs. 



According to Professor Burmeister, the earliest observations on 

 this subject were made known by Schaffer ; then Scopoli described an 

 instance. Communications of this kind then became more numerous. 

 Esyer described a specimen of T. Cratagi, in which the right side 

 was male and the left side female. Then Hetthuger a similar one of 

 B. Quercus. Capieux saw an Hermaphrodite of S. Carpmi, the left 

 wing of which was male, but the right with the rest of the body 

 female. 



Ochsenheimer made a complete list of the Hermaphrodites which, 

 up to his time, had been described, or which he had himself seen or 

 possessed. 



He divided all Hermaphrodites into two groups, viz., into perfect, 

 in which one side was perfectly female and the other perfectly male, 

 and into imperfect Hermaphrodites, where the habit of one sex pre- 



