Between the true naturalist and the mere "collector" there is a wide gap, and I trust that none for whom I am writing will allow themselves to drift into the latter class; the incalculable mischief wrought by those who assist in the extermination of rare and local species by buying up every egg of a certain species which can be obtained, for the mere purpose of exchange, cannot be too much deprecated, and I hope that none of my readers will be so guilty; to them the pleasures of watching the nesting habits of the bird, the diligent search and the successful find are unknown; the eggs in such a cabinet are mere egg-shells, and not objects pregnant with interest, recalling many a happy ramble, and many a hardly-earned reward in the discovery of facts and habits before unknown. Every naturalist must be more or less a collector, but the naturalist should always be careful of drifting into the collector, his note-book and his telescope should be his constant and harmless companions. When the writer first commenced his collection, the mode of preparing the specimens for the cabinet was very rude indeed, and the method of arranging equally bad; he is sorry to say the popular books upon the subject which he has seen do not present any very great improvement; in giving the results of his own experience, and the plan pursued by the most distinguished oologists of the day, who have kindly allowed him to explain the methods they adopt, he will, he trusts, save not only much useless labour, but many valuable specimens. Before saying a word as to preparing specimens for the cabinet, I wish to impress upon the young oologist the absolute necessity for using the greatest care and diligence in order satisfactorily to identify, beyond possibility of doubt, every specimen, before he admits it to his collection. Without such precautions, what might otherwise be a valuable collection is absolutely worthless; and it is better to have a small collection of authentic specimens than a much larger one, the history of which is not perfectly satisfactory; in fact, it is a good rule to banish from the cabinet every egg which is open to the slightest doubt. There are some eggs which, when mixed, the most experienced oologist will find it impossible to separate with certainty, and which cannot be identified when once they are removed from the nest.