THE ENTOMOLOGIST. 101 
upon as a clew, for in individuals which must be admitted to 
be of the same species, size takes a wider extent of difference 
than in almost any of the genera of bees. St. Fargeau, who 
maintains the parasitism of the genus, accounts for it by 
saying that in depositing their eggs in the nests of the 
Andrene, Halicti, and Dasypoda, the Sphekodes resorts to 
the burrows of the species of these genera, indifferent to 
their adaptation to its own size ; and thus, from the abundance 
or paucity of food so furnished to its larvae, does it become a 
large or a small individual. Westwood says they are parasitic 
upon Halictus. Latreille says they are parasites. They are 
certainly just as destitute of the pollinigerous apparatus as 
the preceding genus. Mr. Thwaites once thought he had 
detected a good specific character in the differing lengths of 
the joints of the antenne, but I believe he never thoroughly 
satisfied himself of its being practically available. At all 
events, great difficulty still attaches to their rigid and satisfac- 
tory determination. There is an array of entomologists who 
deny their being parasites. Mr. Kirby says they form their 
burrows in bare sections of sand-banks, exposed to the sun, 
and nine or ten inches deep, and which they smooth with 
their tongues. But then, in impeachment of the accuracy of 
his observation, he further supposes there are three sexes, 
founding his statement upon what Réaumur remarks of 
having observed pupe of three different sizes in the burrows. 
In the first place, it is not conclusive that these pupx were 
those of Sphekodes; and secondly, we know that this condition 
of three sexes is found only in the social tribes, wherein the 
peculiarity of the economy exacts a division of offices. 
Therefore his adoption of this inaccuracy militates against 
the reception of his other statement. But Smith also states 
that they are not parasites, and apparently founds his assertion 
upon direct observation. It still, however, remains a debatable 
point, from the fact of the destitution of the pollinigerous 
brushes, and thence the character of the food necessary to 
be stored for the larva. It would be very satisfactory if 
these apparent inconsistencies could be lucidly explained. 
If, however, it be ultimately proved that Sphekodes is a 
constructive bee, as well as Prosopis, we have still this fact 
exhibited by our native genera, that none of the sub-family 
of short-tonged bees or Andrenide are parasitical. ‘This is a 
