Birds' Eggs

Why is there not a fixed form for all eggs? We can see no reason in the anatomy of the bird, but we may often find reasons for the shape of any particular egg in its later history. It is noticeable, for instance, that the more spherical eggs, as those of owls, trogons and the like, are usually laid in holes ín the earth, rocks or trees, where they cannot t'all out of the nest, and that the eggs of the ordinary song bird, which makes a well constructed nest, are oval, while the slim, straight sided, conoidal eggs, tapering sharply to a point, belong to birds that construct little or no nest - to the shore birds, terns, guillemots and the like. Why? Because these last drop them in small clutches and with little or no preparation upon sand or rock, where, were they spherical, they could only with difficulty be kept closer beneath the sit.ting bird, but conical objects will tend always to roll toward a center. An additional advantage is that eggs of the latter shape will take up less space - form a snugger package to be warined. In the case of guillemots the single egg laid is especially flat sided and tapering, and the species owes its perpetuation largely to this circumstance, educe, were itnot for the egg's toplike tendency to revolve about its own apex, the chances are that it would be pushed off the ledge oí naked sea cliff where the careless or stupid bird leaves it. This suggests a word in reference to the popular fable that sitting birds oarefully turn their eggs every day or oftener in order to warm them equally. No such thiug is done, because unnecessary, since, as we have seeu, the germinal part always rises to the top and places itself nearest the influential warmth of