immature sevuality in Insects. 195 
I shall now consider, at some length, the facts bearing 
upon the above reasons in favour of, and against the views 
I have advanced. 
First. With regard to the early sexual maturity of 
larval forms. 
I have already given instances, in the sexual condi- 
tion, of the larva of Petasia and Ischnodemus, but one of 
the most striking facts of this kind is said to occur 
amongst the Hehinodermata: last summer, Mr. Alex. 
Agassiz related the instance to which I refer, at a meet- 
ing of the Royal Society, at the conclusion of one of Dr. 
Carpenter’s ‘‘ Papers on Deep Sea Life.” It was this 
remark of Mr. Agassiz that first led me to suspect that 
the wingless forms of Hemiptera and Orthoptera might 
have arisen from early maturity of the sexual organs. 
Mr. Agassiz stated, that the young of a Mexican Hehi- 
noderm become sexually mature on the coast of Norway, 
to which its larve are transported by the gulf stream. 
The two sexually mature forms are apparently very dis- 
tinct species, but to anyone who knows the young of the 
Mexican form, the Norwegian species is clearly only an 
immature condition of it, with fully developed sexual 
organs.* 
Second. I have cited the rare appearance of wings in 
certain Hemiptera, in support of my views. The whole 
subject, however, of the correlations of the development 
of the sexual and cutaneous organs in insects is remark- 
ably complex, but I will endeavour to put before you 
some of the more important facts bearing upon it. 
It must be admitted, that the development of the 
female generative organs, and ova, has a very decided 
influence in arresting the development of cutaneous 
organs, in comparison with the development of the cor- 
responding structures in the male, 
It is not a little remarkable that, whilst in Vertebrates 
the male seems to require a higher elaboration (if I may 
use the term with a kind of indefinite meaning), for its 
development, so in insects, the female requires a larger 
supply of nourishment, and more favourable conditions. 
* See Mr. Darwin’s ‘ Descent of Man,’ vol. ii. p. 215, for numerous other 
instances of this nature. Also Mr. Cope, ‘On the origin of genera,’ in 
Proc. Acad. Nat. Se. Philadelphia, Oct. 1868; who I find has already 
arrived at similar conclusions on the effect of retardation and acceleration 
of sexual development, though I cannot follow his deductions. ~ 
