ix 
induced to believe that such is the case, from the early period at which the 
sexual organs first make their appearance in the embryo and larva, from the 
fact that some larvee have been taken in copula, and from an analogous 
phcenomenon which had been observed among the Echinodermata. In the 
course of the paper he had occasion to enter largely into details of correlation 
of development between the cutaneous and sexual organs in insects. He 
stated his belief that such correlations often gave rise to secondary sexual 
characters. The paper concluded with a comparison between acquired and 
direct larval forms. The author thought the larva and pupa of insects were 
probably all acquired, and not direct, stages of development. 
With reference to Mr. Lowne’s remarks on the early development of the 
sexual organs in insects, and with a view of disproving a not uncommon 
idea that the sex is determined by the supply of food (or its quality) 
furnished to the larva, Mr. Briggs detailed some experiments he had 
made. A number of larve of Liparis dispar were separated into two 
divisions, about sixty in each. One lot were fed upon hawthorn, the other 
upon elm. In the elm-fed larvee the imagos produced were about equal as to 
sex, but there were only two perfect females; the males of the ordinary size. 
Tn those fed upon whitethorn, the sexes were again about equal in number, 
but the males were much smaller and paler, whereas the females were much 
finer, and scarcely any of them imperfect. Again, with a view of determining 
whether any truth exists in the statements of old authors that larve differ 
in colour according to sex, Mr. Briggs experimented upon two forms of the 
larva of Trichiura crategi; one form being ringed, somewhat like the larva 
of Bombyx rubi; the other mottled. These forms were figured by Hiitbner 
as of different sexes; but the first-named seemed to be dying out, and was 
described by none of the more recent writers. From a batch of eggs, Mr. 
Briggs obtained about thirty larve of each form: firstly, a male imago, 
produced from a larva of the ringed form, was paired with a female of the 
mottled form; secondly, these conditions were reversed; thirdly and 
fourthly, each form was paired with its like. From these four experiments 
in no one instance was the ringed form of larva obtained; and it did not 
reappear after breeding in to the third generation. 
20 March, 1871. 
A. R. Wattace, Esq., President, in the chair. 
Election of Members. — 
Prof. P. M. Duncan, M.D., F.R.S., &c., and Ernest S$. Charlton, Esq., 
were ballotted for, and elected Members of the Society. 
c 
