of what was previously chaotic in our knowledge of the subject, and cleared the way for all future work upon it. Although recent advances of knowledge have shown that there are difficulties in accepting the whole of Owen's system of homologies and notation of the teeth of mammals, it was an immense improvement upon anything of the kind which existed before, and a considerable part of it seems likely to remain a permanent addition to our means of describing these organs. The close study of the bones and teeth of existing animals was of extreme importance to him in his long continued and laborious researches into fossil forms; and, following in the footsteps of Cuvier, he fully appreciated and deeply profited by the study of the living in elucidating the dead, and vice versa. Perhaps the best example of this is to be seen in his elaborate memoir on the Mylodon, published in 1842, entitled ‘Description of the Skeleton of an Extinct Gigantic Sloth (Mylodon robustus, Owen), with Observations on the Osteology, Natural Affinities, and Probable Habits of the Megatheroid Quadrupeds in General,’ a masterpiece both of anatomical description and of reasoning and inference. A comparatively popular outcome of some of his work in this direction was the volume on ‘British Fossil Mammals and Birds,’ published in 1844–6 as a companion to the works of Yarrell, Bell, and others on the recent fauna of our island. He also wrote, assisted by Dr. S. P. Woodward, the article ‘Palæontology’ for the ‘Encyclopædia Britannica,’ which, when afterwards published in a separate form, reached a second edition in 1861.
To this period of his life belong the courses of Hunterian lectures, given annually at the College of Surgeons, each year on a fresh subject, and each year the means of bringing before the world new and original discoveries which attracted, even fascinated, large audiences, and did much to foster an interest in the science among cultivated people of various classes and professions. They also added greatly to the scientific renown of the college in which they were given. In this period also, being deeply influenced by the philosophy of Oken, he began the development and popularisation of those transcendental views of anatomy—the conception of creation according to types, and the construction of the vertebrate archetype. Such views, though now obsolete, had great attractions and even uses in their day, and were accepted by many, at all events as working hypotheses; around the hypotheses facts could be marshalled, and out of them grew a methodical system of anatomical terminology, much of which has survived to the present time. The recognition of homology, and its distinction from analogy, which was so strongly insisted on by Owen, marked a distinct advance in philosophical anatomy. These generalisations, first announced in lectures at the College of Surgeons, were afterwards embodied in two works: ‘The Archetype and Homologies of the Vertebrate Skeleton,’ 1848, and ‘The Nature of Limbs,’ 1849.
Among the contributions which Owen made to our knowledge of the structure of invertebrate animals, one of the most important was the exhaustive memoir on the pearly nautilus (1833), founded on the dissection of a specimen of this, at that time exceedingly rare, animal, sent to him in spirit by his friend Dr. George Bennett of Sydney. This was illustrated by carefully executed drawings by his own hand. The Cephalopoda continued to engage his attention, and the merits of a memoir on fossil belemnites from the Oxford clay, published in the ‘Philosophical Transactions’ in 1844, was the cause assigned for the award to him of the royal medal in 1846. He contributed the article ‘Cephalopoda’ to the ‘Cyclopædia of Anatomy and Physiology’ (1836), catalogued the extinct cephalopoda in the museum of the Royal College of Surgeons (1856), and wrote original papers on ‘Clavagella’ (1834), ‘Trichina spiralis’ (1835), ‘Linguatula’ (1835), ‘Distoma’ (1835), ‘Spondylus’ (1838), ‘Euplectella’ (1841), ‘Terebratula’ (in the introduction to Davidson's classical ‘Monograph of the British Fossil Brachiopods,’ 1853), and many other subjects, including the well-known essay on ‘Parthenogenesis, or the Successive Production of Procreating Individuals from a Single Ovum,’ 1849.
In 1843 his ‘Lectures on the Comparative Anatomy and Physiology of the Invertebrate Animals,’ in the form of notes taken by his pupil, Mr. W. White Cooper, appeared as a separate work. Of this, a second expanded and revised edition was published in 1855. By this time, as the Royal Society's ‘Catalogue of Scientific Papers’ shows, he had been the author of as many as 250 separate scientific memoirs.
In 1856 Owen began the second period of his career on his migration from the College of Surgeons to the British Museum, where the natural history departments had been placed under his charge, with a salary of 800l. a year. Previously these departments had been under the direct control of a ‘principal librarian’ who had been invariably chosen from the literary side of the establishment.
