(657) 
XXVIIL Parthenogenesis in Worker Ants, with special 
reference to two colonies of Lasius niger, 
Linn. By W. C. CRAWLEY, B.A., F.E.S. 
[Read November 1st, 1911.] 
Ir is generally assumed, according to the theory of 
Dzierzon, that unfertilised eggs of the honey-bee always 
develop into ¢s, and fertilised eggs into Gs and fs. Eggs 
laid by worker bees, which have no spermatheca, will 
therefore produce 3s only. 
This theory has been applied by some authors to ants, 
without sufficient investigation, It is a well-established 
fact that S ants lay eggs. Lespes (1863) indeed asserted 
that such eggs never came to maturity, but Forel (1874) 
records Gs of Formica sanguinea laying eggs which 
produced Zs. Denny showed that Gs lay eggs, and 
Dewitz (1879) maintained that the gs habitually lay 
eggs, 
* ‘Lubbock (1890) carried out careful observations on 
queenless colonies of Formica cinerea, F. fusca, Polyergus 
rufescens, and Lasius niger, and found that eggs were laid 
by the $s, but only ¢s were produced from these eggs. 
In colonies of /. fusca, and F. sanguinea with fusca 
slaves, I have often observed the §s to lay eggs, but no 
ds came to maturity in any of the nests, and the sanguinea 
Qs appeared to devour most of the eggs almost as soon as 
they were laid. The first indication that eggs laid by 3 
ants might produce Gs as well as fs seems to be in a 
paper by Reichenbach (1902). Reichenbach obtained 
some three hundred Gs and two or three dozen fs from 
the eggs laid by a small queenless colony, containing only 
a few Gs, of Lasius niger. Mrs. Comstock (Wheeler, 1903), 
obtained similar results with ZL. niger var. americanus. 
In a recent paper (1909) Janet criticises Reichenbach’s 
experiment, suggesting that he should repeat it, taking the 
most minute precautions against error. Janet himself 
made attempts to obtain $s from & eggs with no less 
than thirty queenless colonies of several species, under 
TRANS. ENT. SOC. LOND. 1911.—PART Iv. (JAN. ) 
