The following interesting account of a pair of Nuthatches engaged in making their nest, is from the pen of a contributor to a periodical called "The Naturalist;" the date of the occurrence was the 18th. of April.--"The birds had fixed upon a hole in an ash tree, about twenty feet from the ground, and were contracting it with a plastering of mud, for which they flew to a small pond about fifty yards distant from the tree, and took pieces in their beaks about as big as a bean, which they laid on, and smoothed with their chin. Sometimes one of them would go inside and remain for a short time, I suppose for the purpose of smoothing the mud there. They would every now and then leave off from their task, and chase one another up the trunk and round the branches of the tree with amazing rapidity, uttering all the while their flute-like whistle. They both seemed to take an equal share in the labour; and had, like the House Martin, small pieces of straw mixed with the mud, for the purpose of making it bind better. They seemed to be quite at ease on the ground, and hopped about much after the same manner as the Sparrow. The male bird was easily distinguishable by his brighter plumage." CUCKOO. COMMON, OR GREY CUCKOO. GOWK, OR GECK. COG, OF THE ANCIENT BRITISH. FIGURE 14. Of the _Cuculine_ Birds, or Cuckoos, none are permanently resident in countries subject to severe winter cold. They feed mostly on insects, worms, or soft fruit, gliding amid the trees in search of their food in a peculiarly rapid and noiseless manner. In passing from branch to branch they generally leap; they do not climb like the Woodpeckers and Creepers, although they have much the same conformation of feet, the outer toe being directed backwards, as well as the first; this is called _Zy-go-dac-ty-lous_, a Greek word, signifying that the toes are yoked, or in pairs, two before and two behind. We have thought it well to introduce this queer word to our readers, lest they should stumble over it, as they are likely to do, in many works on Natural History which they may consult, and be frightened at its uncouth appearance; they will now know what is meant by _zygodactylous_, or _dactytic_ birds, such as Owls, Woodpeckers, Cuckoos, etc. But having explained thus much, we should go a step farther, and introduce also _A-ni-so-dac-ty-lous_, Greek again, meaning unequally yoked, that is, when there is a wider interval between one pair of toes than between the other.