252 Dr. F. Plateau on the Production of the Sexes in Bees. 
and which are at any rate in the same category, viz. a Siga- 
lion, a Syllis, an Autolytus, an Amage, and a Polycirrus. 
I may also remark, in passing, with reference to some of the 
other known forms found in this collection, that the Halosydna 
Jeffreysti, Lankester*, is H. gelatinosa, Sars{, as men- 
tioned in Dr. Giinther’s Zoological Record for 1866, and that 
I have not yet been able to make out a specific difference be- 
tween Leodice norvegica, Linn., and Eunice Harassii, Aud. 
& Ed.t 
In addition to the Annelids proper, there were some Plana- 
rians, Ommatopleans, Borlasians, and a very remarkable form 
allied to the latter group, with a bifid proboscis—besides a 
boring Sipunculus, lodged in its cavity mside a fragment of 
shell. 
XXIX.—On the Production of the Sexes in Bees. 
By Feurx Puateav, D.Sc. 
To the Editors of the Annals and Magazine of Natural History. 
Ghent, Sept. 9, 1868. 
GENTLEMEN, 
Having been occupied for a long time with investigations 
upon the parthenogenesis of the Invertebrata, I have read 
with eagerness the interesting notice by M. von Siebold “* On 
the Law of Development of the Sexes in Insects,” in which 
the learned Professor endeavours to refute the assertions and 
experiments of M. Landois. 
The theories of Dzierzon and of Von Siebold, ingenious as 
they are, and notwithstanding the numerous facts which are 
cited in their support, seem nevertheless to be so much in con- 
tradiction to our general knowledge of the reproduction in the 
higher animals, that researches such as those of M. Landois 
should be received with favour, and we ought to take care 
not to reject them without having exhausted all possible argu- 
ments in connexion with them. 
M. von Siebold, indeed, passes over in complete silence 
some very important observations which seem to me to be 
entirely in favour of M. Landois. Androgynous or herma- 
phrodite bees have been remarked long since by a school- 
master named Lucas; and more recently this monstrosity has 
been observed by MM. Doenhoff, Menzel, and Engster ; 
* Trans, Linn. Soc. vol. xxv. p. 377, tab. 51. figs. 12, 19, 26. 
+ Beskriv. og Jagtt. &c. 1835, p. 63, pl. 9. fig. 25. 
{ Hist. Nat. du Litt. de la France, ii. p. 141, pl. 3. fig. 5, 6, 7, 10, & 11. 
