Scarcely had he finished the twelve volumes of Quadrupeds when Buffon turned to the Birds. If this section were less exacting, yet it made enormous claims upon his attention, and nine volumes were occupied before the history of the class was concluded. Publication of "Des Oiseaux" was begun in 1770, and continued intermittently until 1783. But troubles dogged the great naturalist. The relations between him and Daubenton had grown acute, and the latter, unwilling any longer to put up with Buffon's love of vainglory, withdrew from the enterprise to which his co-operation had imparted so much value. Serious illness, also, and the death of Buffon's wife, caused a long suspension of his labours, which were, however, lightened by the assistance of Gueneau de Montbeliard. One stroke of luck he had, which no one will begrudge the weary Titan. James Bruce, of Kinnaird, on his return from Abyssinia in 1773, spent some time with Buffon at his chateau in Montbard, and placed at his disposal several of the remarkable discoveries he had made during his travels. Buffon was not slow to appreciate this godsend. Not only did he, quite properly, make the most of Bruce's disinterested help, but he also expressed the confident hope that the British Government would command the publication of Bruce's "precious" work. He went on to pay a compliment to the English, and so commit them to this enterprise. "That respectable nation," he asserts, "which excels all others in discovery, can but add to its glory in promptly communicating to the world the results of the excellent travellers' researches." Still unfettered by any scheme of classification, either scientific or logical, Buffon begins his account of the birds with the eagles and owls. To indicate his course throughout the vast class, it will suffice to name a few of the principal birds in the order in which he takes them after the birds of prey. These, then, are the ostrich, bustard, game birds, pigeons, crows, singing birds, humming birds, parrots, cuckoos, swallows, woodpeckers, toucans, kingfishers, storks, cranes, secretary bird, herons, ibis, curlews, plovers, rails, diving birds, pelicans, cormorants, geese, gulls, and penguins. With the volume dealing with the picarian birds (woodpeckers) Buffon announces the withdrawal of Gueneau de Montbeliard, and his obligations for advice and help to the Abbe Bexon (1748-1784), Canon of Sainte Chapelle in Paris. _III.--Supplement and Sequel_