604 THE HOME OF THE BEES. 
This parasitism does not go far enough to cause the death 
of the host, since we find the young of the parasitic 
Nomada, or Cuckoo-bee, in cells containing its young. 
Mr. F. Smith, in his “Catalogue of British Bees,” says 
of this genus: “No one appears to know anything beyond 
the mere fact of their entering the burrows of Andrenide 
and Apide, except that they are found in the cells of the 
working bees in their perfect condition: it is most proba- 
ble that they deposit. their eggs on the provision laid up 
by the working bee, that they close up the cell, and that 
the working bee, finding an egg deposited, commences a 
fresh cell for her own progeny.” 
He has, however, found two specimens of Nomada sex- 
fasciata in the cells of Hucera longicornis, the Long-horned 
bee. He also states, that while some species are constant 
in their attacks on certain Halicti and Andrene, others 
attack different species of these genera indiscriminately. 
| like manner another Cuckoo-bee ( Celionys) is para- 
sitic on Megachile and Saropoda; Stelis is a parasite on 
Osmia, the Mason-bee ; and Melecta infests the cells of 
Anthophora. 
The observations of Mr. Emerton enable us still far- 
ther to clear up the history of this obscure visitor. He 
found both the larva and pupa, as well as the perfect bee, 
in the cells of both genera; so that either both kinds of 
bee, when hatched from eggs laid in the same cell, feed on 
the same pollen mass, which therefore barely suffices for 
the nourishment of both ; or the hostess, discavering the 
strange egg laid, cuckoo-like, in her own nest, has the 
forethought to deposit another ball of pollen to secure the 
safety of her young. | 
As such an act the operation of a blind instinct? Does 
it not rather ally our little bee with those higher animals 
