WILLIAM, an eminent English naturalist, and one of the earliest, and still the most popular of British entomologists, was born in 1759, at Wintesham, in Suffolk. Sent first to the school of his native village, and afterwards to the grammar school of Ipswich, he removed in due course to Caesars College, Cambridge, where he took his bachelor's degree in 1781. In the following year he entered the church, and was appointed to the curacy of Barham, which office he held for fourteen years. Such time as he could steal from his pastoral duties he devoted at this period of his life to botany, of which he was an ardent student. The rector of the parish adjoining his was William Jones, well known as the author of a work on the Trinity. Under the influence of this able controversialist, Kirby's views of religion and politics became fixed and confirmed. Pious, and sincerely evangelical in his preaching, he was a strong supporter of government, and was even induced to use his pen in countering the spirit of free-thinking then reacting from France upon England. But he had little taste for controversy, and, retiring from that field, he devoted himself wholly to his favourite study of natural history. In a letter to a friend he describes how his attention was first drawn to the science of entomology. "Observing, accidentally, one morning a very beautiful golden bug (the lady-bird, or cow-lady, Coccinella, 22 punctata), creeping on the sill of my window, I took it up to examine it, and finding that its wings were of a more yellow hue than was common to my observations of these animals before, I was anxious carefully to examine any other of its peculiarities, and finding that it had twenty-two beautiful clear black spots upon its back, my captured animal was imprisoned in a bottle of gin for the purpose, as I supposed, of killing him. On the following morning, anxious to pursue my observation, I took it again from the gin and laid it on the window-sill to dry, thinking it dead, but the warmth of the sun very soon revived it; and hence commenced my further pursuit of this branch of natural history. Encouraged by some of the local naturalists to persevere, he made frequent entomological excursions, and greatly enlarged his knowledge of the science. When the Linnean Society was founded in 1788 by Sir J. E. Smith, Kirby immediately became a member, and contributed many valuable papers to its Transactions. The first separate work by which he made his name widely known was his Monographia Apum Anglicae, published at Ipswich, in 2 vols., in 1802. This, as the first scientific treatise on the bees of England, brought him into notice with the leading entomologists, not only of his own country, but also of the Continent; and from this time he corresponded frequently with Latreille, Fabricius, Illiger, Walckenaer, and other eminent naturalists in France and Germany. In 1805 Kirby had formed the acquaintance of Mr Spence, a scientific gentleman of Hull, whose studies had lain very much in the same direction as his own. Three years later the two friends struck out between them the idea of popularizing the science which both had pursued with so much pleasure and benefit to themselves. The practical result of this idea was the work known as Kirby and Spence's Introduction to Entomology, one of the most popular books of science that has ever appeared in any tongue. The first volume was published in 1815; a second edition of it was called for in the following year, and a third in 1817, when, also, was published volume ii., of which a second edition was required in 1818, and a third in 1822. The bad health of Mr Spence interrupted the progress of the work for some years, and the concluding volumes (iii. and iv.), did not see the light till 1826. Seven editions (the last of them in 1856), prove that its popularity continues undiminished. The form and Kircheim style of the work were eminently calculated to ensure success. A series of familiar letters, couched in easy and almost gossiping terms, is made the vehicle of strictly scientific information on the structure, habits, uses and instincts of the insect world. Of the fifty-one letters comprised in the series, thirteen were written solely by Kirby, and eight by Spence, while the remaining thirty were produced conjointly. The appendix was supplied by Kirby, and the preface by his collaborateur.

In 1830, Kirby, though then in his seventieth year, was appointed to write one of the Bridgewater Treatises. He chose as his subject the Habits and Instincts of Animals, with reference to Natural Theology. The wide range of his theme drew him beyond his own proper province, and led him into tracks with which he was less familiar. But though his Treatise fell short of his earlier works in point of scientific value, it was admitted to have admirably fulfilled the purposes of the Bridgewater trust. The most important of his other works was his description of the insects introduced in Sir John Richardson's Fauna Boreali-Americana. A volume of sermons which he published in 1829, met with no great success.

Kirby never obtained any preferment in the church commensurate with his deserts. For fourteen years he remained curate of Barham, and in 1796, on the death of the rector of the parish, he was appointed his successor. He held the living till his death, on the 4th July 1850. Before he died, he had the satisfaction of seeing a knowledge of his favourite science widely disseminated throughout England, and numerous societies formed for its advancement. He was himself a member of most of the scientific corporations in England, on the Continent, and in the United States. A very detailed biography of him, by his friend the Rev. John Freeman, M.A., was published in London in 1852. The most valuable chapter in that work is contributed by Mr. Spence, and from it most of the details of this notice have been taken. (See art. Entomology.)