On the Development of the Sexes in Insects. 205 
of Rhynchonella, &e., and concluding with the following pas- 
sage :— 
“But let me not forget to acknowledge that I was in error 
in doubting the absence of perforations ‘in any Brachiopod 
whatever :’ the account which Dr. Carpenter has given of 
Rhynchonella psittacea in his late chapter* is quite conclusive 
on this point; but I cannot help thinking, from their occurring 
in #.? Geinitzianat, that perforations will yet be found in 
congeneric species supposed, or stated, to be without them’’t. 
The way Dr. Carpenter writes with reference to my volun- 
tarily acknowledged error, also the other “remarks” he has 
indulged in in his letter, will, I feel assured, be quite sufficient 
to convince the “ scientific world” that, for anything more he 
can adduce, the “main question”? (7. e. the “‘ remarkable fact 
incontestably established’) at issue between us is, as far as 
we are mutually concerned, now closed,—that, if kept open, it 
would inevitably degenerate into a mere personal dispute, 
redundant of reticences, and bolstered up with no end of 
irrelevant matter. , 
: Yours very truly, Ke. 
WILLIAM KING. 
XXI.—On the Law of Development of the Sexes in Insects. 
By Professor Von SreBoip§. 
THE assertion made by Landois in his preliminary communi- 
cation {] that the eggs laid by insects possess no definite traces 
of the sexual organs, and that the sex of the larve is only 
developed as male and female after their escape from the egg- 
shell by the influence of difference of food received from with- 
out, will not only possess the highest interest for all naturalists 
who attend to the reproductive history of organic bodies, but, 
as Landois applies this theory specially to the reproduction of 
* Reference is here made to Dr. Carpenter’s memoir “ On the Intimate 
Structure of the Shells of Brachiopoda,” appended to Mr. Davidson’s 
Monograph of Brit. Foss. Brachiopoda: Introduction. A perusal of my 
footnote will explain the reason why I only referred to Dr. Carpenter’s 
“late chapter.” 
+ The presence of perforations in this species has caused me to regard 
it as the type of anew genus (Rhynchopora) of the family Rhynchonellide. 
¢ See Ann. & Mag. Nat. Hist. ser. 2. vol. xvii. p. 337. Even in June 
(Geological Magazine) of last year I again drew attention to this point, 
acknowledging “the mistake I made in asserting that certain imperforate 
Palliobranchs are perforated,” and in “ concluding that all Spiriferide are 
perforated.” 
§ Translated by W.S. Dallas, F.L.S., from the Zeitschrift fiir wis- 
sensch. Zoologie, Band XVii. Pp. 525-532. 
4] See Zeitschrift fiir wiss. Zool. xvii. p. 375, and Ann, & Mag. N. H. 
ser. 3. vol. xix. p. 224. 
Ann.& Mag. N. Hist. Ser. 4. Vol. ii. 105) 
