2S4« On the Natural History of the Bee, 



3. Compound Eyes mth Facets. — These contain, behind 

 thin or prismatic facets, transparent bodies connected with 

 the filaments of the optic nerve, and having their lateral 

 surfaces coated with a pale or dark-coloured, but in all cases 

 opaque, pigment. They are found in the perfect Crustacea 

 and insects. 



In most insects and Crustacea the transparent bodies are 

 longer than they are broad; forming, in the direction of 

 their axes, transparent cones or cylinders, of variable length. 

 There are, however, a few instances in which these trans- 

 parent bodies behind the cornea are of extremely small 

 extent in the direction of their axes, less so indeed than in 

 the transverse direction; as in the Fespa Crabro, Libellula 

 quadrimaculata, ^schna grandis, and in different species 

 of fly. 



4. Compound Eyes without Facets, — To this division be- 

 long the eyes of the Monoculi, and of a few others of the 

 inferior Crustacea. 



These eyes contain, behind a common and transparent 

 cornea without facets, certain crystalline bodies, rounded 

 above and pointed below ; the apices or points being inserted 

 in a stratum of dark pigment, above which the rounded 

 heads project. The apices are connected with the filaments 

 of the optic nerve. These crystalline bodies are either long 

 and conical, as in the Monoculus apus; or short and 

 pyriform, as in the Daphniae and Gammarus Pulex. Their 

 number is very considerable in the Monoculus apus, ap- 

 proximating in this respect to the cones in the compound 

 eyes of insects ; smaller in the Gammarus, and still less in 

 the other Monoculi and in the whale louse (Cyamus Ceti). 



(To be continued.) 



Art. IX. On the Natural History of the Bee. 

 By W. L., of Selkirkshire. 

 Sir, 

 It seems to have been ascertained that every bee that 

 leaves the hive in the morning gathers honey and pollen from 

 only one species of flower throughout the day, adhering closely 

 to the species. 



From my own observations I have been constrained to 

 acquiesce in this curious fact. Bnt we always find that 

 every habit of insect, bird, or beast, has a positive use, or 

 corresponds to some law of its existence, and there appeared 

 nothing to induce us to suppose this habit of bees to be ano- 



