HISTORY.] ANATOMY 811 work of Malpigiti on the structure of the lungs, several sketches in the writings of Mayow, and other treatises of less moment. Systematic treatises of anatomy began to assume a more instructive form, and to breathe a more philosophical spirit. The great work of Adrian Spigelius, which appeared in 1627, two years after the death of the author, contains indeed no proof that he was aware of the valuable generalisation of Harvey ; but in the institutions of Caspar Bartholin, as republished and improved by his son Thomas in 1651, the anatomical descriptions and explanations are given with reference to the new doctrine. A still more unequivocal proof of the progress of correct anatomical knowledge was given in the lectures delivered by Peter Dionis, at the Jardin Royal of Paris, in 1673 and the seven following years, in which that intelligent surgeon gave most accurate demonstrations of all the parts com posing the human frame, and especially of the heart, its auricles, ventricles, and valves, and the large vessels connected with it and the lungs. These demonstrations, first published in 1690, were so much esteemed that they passed through seven editions in the space of thirty years, and were translated into English. The progress of anatomical discovery continued in the meantime to advance. In the course of the 1 6th century Eustachius, in studying minutely the structure of the vena azygos had recognised in the horse a whito vessel full of watery fluid, connected with the internal jugular vein, on the left side of the vertebral column, corresponding accu rately with the vessel since named thoracic duct. Fallopius also described vessels belonging to the liver distinct from arteries and veins ; and similar vessels appear to have been noticed by Nicolaus Massa. The nature and properties of these vessels were, however, entirely unknown. On the 23d July 1622 Gaspar Asellius, professor of anatomy al Pavia, while engaged iu demonstrating the recurrent nerves in a living dog, first observed numerous white delicate filaments crossing the mesentery in all directions; and though he took them at first for nerves, the opaque white fluid which they shed quickly convinced him that they were a new order of vessels. The repetition of the experiment the following day showed that these vessels were best seen in animals recently fed ; and as he traced them from the villous membrane of the intestines, and observed the valves vith which they were liberally supplied, he inferred that they were genuine chyliferous vessels. By confounding them with the lymphatics, he made them proceed to the pancreas and liver, a mistake which appears to have been first rectified by Francis De le Boe. The discovery of Asellius was announced in 1627 ; and the following year, by means of the zealous efforts of Nicolas Peiresc, a liberal senator of Aix, the vessels were seen in the person of a felon who had eaten copiously before execution, and whose body was inspected an hour and a half after. In 1629 they were publicly demonstrated at Copenhagen by Simon Pauli, and the same year the thoracic duct was observed by Mentel for the first time since it was described by Eustachius. Five years after (1634), John Wesling, professor of anatomy and surgery at Venice, gave the first delineation of the lacteals from the human subject, and evinced more accurate knowledge than his predecessors of the thoracic duct and the lymphatics. Highmore in 1637 demonstrated unequivocally the difference between the lacteals and the mesenteric veins ; and though some per plexity was occasioned by the discovery of the pancreatic duct by Wirsung, this mistake was corrected by Thomas Bartholin; and the discovery by Pecquet in 1647 of the common trunk of the lacteals and lymphatics, and of the course which the chyle follows to reach the blood, may be regarded as the last of the series of isolated facts by the generalisation of which the extent, distribution, and uses of the most important organs of the animal body were at length developed. To complete the history of this part of anatomical science one step yet remained, the distinction between the lacteals and lymphatics, and the discovery of the termination of the latter order of vessels. The honour of this discovery is divided between Jolyffe, an English anatomist, and Olaus Eudbeck, a young Swede. The former, according to the testimony of Glisson and Wharton, was aware of the distinct existence of the lymphatics in 1650, and demonstrated them as such in 1652. It is nevertheless doubtful whether he knew them much before the latter period ; and it is certain that Rudbeck observed the lymphatics of the large intestines, and traced them to glands, on the 27th January 1651, after he had, in the course of 1650, made various erroneous conjectures regard ing them, and, like others, attempted to trace them to the liver. The following year he demonstrated them in presence of Queen Christina, and traced them to the thoracic duct, and the latter to the subclavian vein. Their course and distribution were still more fully investigated by Thomas Bartholin, Wharton, Swammerdam, and Blaes, the last two of whom recognised the existence of valves ; while Antony Nuck of Leyden, by rectifying various errors of his predecessors, and adding several new and valuable observations, rendered this part of anatomy much more precise than formerly. After this period anatomists began to study more minutely the organs and textures. Francis Glisson distin- 1654. guished himself by a minute description of the liver, and a clearer account of the stomach and intestines, than had yet been given. Thomas Wharton investigated the structure 1656. of the glands with particular care ; and though rather prone to indulge in fanciful generalisation, he developed some interesting views of these organs ; while Charleton, who appears to have been a person of great genius, though addicted to hypothesis, made some good remarks on the communication of the arteries with the veins, the foetal circulation, and the course of the lymphatics. But the circumstance which chiefly distinguished the history of anatomy at the beginning of the seventeenth century was the appearance of Thomas Willis, who rendered himself Willis, eminent not only by good researches on the brain and nerves, but by many judicious observations on the structure of the lungs, the intestines, the blood-vessels, and the glands. His anatomy of the brain and nerves is so minute and elaborate, and abounds so much in new information, that the reader is struck by the immense chasm between the vague and meagre notices of his predecessors, and the ample and correct descriptions of Willis. This excellent . work, however, is not the result of his own personal and unaided exertions; and the character of Willis derives additional lustre from the candid avowal of his obligations to Wren and Millington, and, above all, to the diligent researches of his fellow-anatomist Richard Lower. Willis was the first who numbered the cranial nerves in the order in which they are now usually enumerated by anatomists. His observation of the connection of the eighth pair with the slender nerve which issues from tho beginning of the spinal chord is known to all. He remarked the parallel lines of the mesolobe, afterwards minutely described by Vicq d Azyr. He seems to have recognised the communication of the convoluted surface of the brain and that between the lateral cavities beneath the fornix. He described the corpora striata and optic thalami; the four orbicular eminences, with the bridge, which he first named annular protuberance; and the white mam- miilary eminences, behind the infundibulum. In the cerebellum he remarks the arborescent arrangement of the
white and grey matter, and gives a good account of the
