Botanical Society of Edinburgh. 423 Museum of the College of Surgeons, and cannot see that it has even a title to generic distinction. Naturalists seem at all times to have been prone to assign generic rank to whatever was mysterious or difficult to classify, and I can in no other way account for this species being made a genus. It will be seen that my endeavour has been rather to ascertain and demonstrate whatever natural degrees of relationship exist among the species of this family, than to compose a system for mere convenience of reference ; but so far from that being any hindrance to the prac-tical adoption of my views, I think that in arranging the specimens in a museum, or the materials of a work, it will generally be found more convenient to be able to dispose the members of a natural group in whatever order may suit our immediate object, than to be com-pelled to place them in accordance with the stringent laws of a purely analytical method ; and that for the purpose of referring a new species to its true location, when we have not the means of observing all characters that may be necessary for the determination of a series of natural affinities, the external characters which can be assigned to a group when its limits are well made out, will be found sufficient ; while on the other hand, not only the external characters, but some-times even those of anatomical structure, will, in a group which has not been previously subjected to a full and careful examination, be as the letters of an unknown language, often leading into error and confusion. With regard to nomenclature, I have used such names as I find most generally adopted by later naturalists who have given attention to this subject, generally taking, where I had a choice, such as appeared to have been of earliest date ; and as I only enumerate such species as I have seen, I must not be considered, although I have omitted a few which appear to be varieties, as rejecting all that are left out. BOTANICAL SOCIETY OF EDINBURGH. Thursday, 10th of July, 1851. Dr. Balfour exhibited specimens of the following monstrosities : — 1 . An Arum with a double spathe, the second spathe being alter-nate with the first. The spadix at the lower end showed the appear-ance of the adhesion of a second spadix. This specimen was from the garden of Dr. Neill, Cannonmills Cottage. 2. A monstrosity of Antirrhinum majus, presenting a regular flower formed by five personate petals with gibbous bases. 3. Monstrosity of white Digitalis showing the terminal floret com-posed of several united, and expanding before the other flowers in the raceme. There was thus a mixed inflorescence, partly definite and partly indefinite. A letter was read from Mr. Wyville Thomson, Lecturer on Botany, King's College, Aberdeen, in which he states: — "A few days ago, walking along Dee-side about seven miles above Aberdeen, I was much surprised to see Prunus spinosa covered with large handsome fruit
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