They thus put forward claims to attention and must excite curiosity by their beauty and size, which the comparative smallness of our own, and the usual dulness of their colours do not possess. The latter only repay notice upon close investigation, but they then as amply reward all labour bestowed upon them by the mental recreation they yield, as their more gaudy exotic rivals. The former present themselves obtrusively and exact notice, whereas ours meekly solicit it by their humble but solid allurements. Here, as well as there, we behold the works of a mighty hand and of an immeasurable intelligence. The bees throughout the world, as known collectively to the richest cabinets, number about two thousand species. This host, in itself numerically so large, solicits attention, for it is opposed to the economy of nature that there should exist any without functions of essential usefulness, making them important elements in her harmonious order and necessary to her due course, irrespective of the instruction to be derived from the study of the manifold varieties of structure, which unquestionably point to distinguishing peculiarities of habits. In the true bees the division of the _Dasygasters_ presents the fewest differing generic forms: the _Nudipedes_ and _Scopulipedes_ exhibit more numerous varieties, the preponderance being in favour of the pollen-collecting bees (the latter), although the cuckoo-bees (the _Nudipedes_) are very abundant, and taken _en masse_, are certainly the handsomest. If it be absolutely the case that there are no parasites amongst the _Andrenidæ_, this subfamily will add very largely to the exotic pollinigerous majority, which thereby becomes extensively subservient to the fruition of the vegetable kingdom. Those bees which are exclusively inter- or sub-tropical, seem furnished with larger capacities for fulfilling the special mission to which the family is appointed. Their pollinigerous and honey-collecting organs are peculiarly adapted both to the structure and luxuriance of the superb vegetation of those regions, and to which they seem distinctly limited. But that they are not considered equivalent to the entire demand of the profuse bloom everywhere abounding, may be concluded from the tropical range and distribution of many of our northern forms. Thus, whilst the flora of those climates is strictly circumscribed in its diffusion, its fauna, distinctly in the class of insects, and especially in the family of bees, is very considerably less limited, in extension.