PARASITES OF THE TETTIGID^. 45 



out." The host soon died from exhaustion. I can 

 find no notice of the species of insect bred from this 

 pupa.^ — (See Ent. Mo. Mag. vol. xix. p. 117.) 



The egg of Gonatopus is probably at first glutinous, 

 and, shortly after deposition, a penetration is effected 

 through the soft connexivum between the horny rings 

 of the body, when its contents undergo the change 

 previously noted. 



In the ' Trans. Ent. Soc. of London ' for 1876 may 

 be found some short notes relating to the parasites 

 of some exotic Fulgoridse. 



Prof. Boheman, some years before, had succeeded 

 in breeding, from the bodies of Thamnotettix sidphurella, 

 a minute dipterous insect, Pipuncidus fuscipcs, Fall., 

 and he found that another gnat-like insect also attacks 

 Limotettix virescens. 



Although much has been written upon the subject 

 of parasitism, it is not at all easy to define any strict 

 natural law through or by which these extraordinary 

 propensities have arisen. As a rule it may be stated 

 that the larger number of Acari are vegetable feeders. 

 Whence comes it, if the original forms had vegetable 

 habits, that the subsequently produced predacious 

 and parasitic kinds should be correlated, not in one but 

 in several of their organs, for such a totally different 

 habit of life ? 



It is pretty generally admitted that parasitic forms 

 are more or less of a degraded type, and it has been put 

 forward that the abortive organs and members of their 

 bodies have, in a great measure, arisen through some 

 process of deterioration by non-use. It might be anti- 

 cipated that any animal, seeking its sustenance under 

 any conditions of competition, would be active in habit, 

 with its limbs fitted for searching and obtaining its 

 nourishment. On the other hand, we may conceive 

 that any animal surrounded by its food, where no 

 struggle is required for its acquisition, might undergo 

 abortion and final loss as to certain of its limbs or 

 organs. In some such manner we might think that a 



