verifying the nomenclature of the Flora. Circumstances which we need not enter upon here have caused it to be broken into two halves and divided between the Museum at Newcastle and the Linnean Society in London. The collections of Robertson and an interleaved copy of the Guide of 1805, with copious annotations, are in the Newcastle Museum. The collection of the late Wm. Backhouse, of Darlington, was unfortunately consigned to the hands of Mr. Baker for use in the preparation of this work when his herbarium and library were totally destroyed by fire in 1864 and perished in the conflagration, as did also a large number of plants gathered by the late Mr. John Storey, which were the property of the Blyth Mechanics' Institute. Besides these, we have been indebted to the Rev. W. W. Newbould for comparing our Catalogue, after it was written out, with the herbarium of Professor Oliver, now the property of University College, London.
Classes of Citizenship.—A point which requires to be carefully attended to in enumerating the plants of any particular district, is to draw a line of distinction as clearly as circumstances will allow between those which really belong to it as aboriginal inhabitants and those which owe their introduction to human intervention. In any long-settled, long-cultivated tract of country, the modification which has been brought about by human agency is, of necessity, very considerable. Around the place where man fixes his dwelling swamps, moors, and woods disappear to make way for cultivated fields, roads, and gardens: the bog, heath, and shade-loving plants are restricted in their range or altogether exterminated; and the places which these occupied are filled up by the species which man grows for food or other purposes and the weeds which these bring in their train. Out of the eleven hundred and thirty-seven enumerated in the following list, we can only claim with confidence eight hundred and forty-four as genuine natives. But a considerable proportion of the introductions are now very thoroughly settled down. Following the nomenclature of the Cybele Britannica we have called the well-established agricultural weeds by the name of Colonists, and the
