272 THE ENTOMOLOGIST. 
emergence would give rise to a partial second brood, and finally 
the insect would become regularly and completely double- 
brooded, as is now the case in the warmer parts of Central 
Europe. In Great Britain the species is  single-brooded, 
except in the South of England, where, as I have previously 
adverted to, it still retains its original habit as a single-brooded 
insect in part, though it is at the same time gradually merging 
into a double-brooded state. By the time this change is 
completely effected the single-brooded element will probably 
have ceased to exist in this species in the South of England. 
The British entomologist of the future, who may consider the 
double-brooded insect of the south distinct from its single- 
brooded brother of the north, will perhaps have nothing more 
trustworthy than colour and ornamentation to guide him in 
forming his separate series of each, unless he should consider 
all northern specimens biwndularia, and all southern examples 
crepuscularia, without regard to such unstable characters as 
marking and coloration. 
12, Abbey Gardens, St. John’s Wood, N.W. 
BOMBYX QUERCUS, CALLUNA, OR ROBORIS ? 
By Miss K. M. Hincatirr 
Wi. someone disentangle the synonymy of Bombyx quercus, 
and describe its varieties? I have two varieties (or species) of 
this insect, one taken in England, the other in France, and am 
totally at a loss to name them, for every author and list-compiler 
seems to have different and conflicting views on the subject. 
Newman describes and figures one species, quercus (the one I 
have taken in this country), simply mentioning callune as being 
longer in pupa. Kirby, on the contrary, calls Newman’s 
quercus, callune, and describes as quercus the one | have taken 
abroad, which is decidedly redder in colouring, and has the band 
on the hind wings less curved; he makes no mention of roboris. 
Staudinger’s Catalogue of 1861 gives one species, quercus, with 
ab. roboris and y. callune, his later one changing to v. roboris 
and ab. callune. Doubleday, in the 2nd edition of his Catalogue, 
published in 1866, makes roboris a variety of quercus, but callune 
