1.] APPENDIX. 39 



or it is at any rate never more than a vita minima, with a re- 

 duction of assimilation to its lowest point. 



The following account does not make any claim to contain all 

 or even most of the facts scattered through the enormous mass 

 of entomological literature, and much less all that is privately 

 known by individual entomologists. It must therefore be 

 looked upon as merely a first attempt, a nucleus, around which 

 the principal facts can be gradually collected. It is unnecessary 

 to give any special information as to the duration of larval life, 

 for numerous and exact observations upon this part of the 

 subject are contained in all entomological works. 



I. Orthoptera. 



Gryllotalpa. The eggs are laid in June or July, and the young 

 are hatched in from two to three weeks ; they live through the 

 winter, and become sexually mature in the following May or 

 June. 'When the female has deposited her eggs, her body 

 collapses, and afterwards she does not survive much longer 

 than a month.' 'According as the females are younger or 

 older, they live a longer or shorter life, and hence some females 

 are even found in the autumn' (Rosel, 'Insektenbelustigungen,' 

 Bd. II. p. 92). Rosel believes that the female watches the eggs 

 until they are hatched, and this explains the fact that she out- 

 lives the process of oviposition by about a month. It is not 

 stated whether the males die at an earlier period. 



Gryllus campestris becomes sexually mature in May, and 

 sings from June till October, 'when they all die' (Oken, 

 ' Naturgeschichte,' Bd. II. Abth. iii. p. 1527). It is hardly 

 probable that any single individual lives for the whole summer ; 

 probably, as in the case of Gryllotalpa, the end of the life of 

 those individuals which first become mature, overlaps the 

 beginning of the life of others which feach maturity at a later 

 date. 



Locusta viridissima and L. verrucivora are mature at the end 

 of August ; they lay their eggs in the earth during the first 

 half of September and then die. It is probable that the females 

 do not live for more than four weeks in the mature state. It is 

 not known whether the males of this or other species of locusts 

 live for a shorter period. 



I have found Locusta cantans in plenty, from the beginning 



