276 AGASSIZ It was by these great undertakings that he chiefly won his distinguished position as one of the greatest leaders in scientific research; but his observant faculties were by no means concentrated upon them exclusively. His intellec tual tentacula expanded in every direction. The history of the Belemnites, the muscular system of recent and fossil shells, the principles of classification of the animal king dom, the embryology of the salmon, and critical studies of special genera of fossil Mollusca all engaged his attention. During his travels in England in 1834 he was ever on the alert for new specimens for the museum at Neuchatel. One characteristic incident of this kind may be referred to here. A fine porpoise had been caught by the Scarborough fishermen. Agassiz was Aveary with travel, and had but a few hours to remain in the town, but the chance could not be allowed to escape ; the creature was purchased, and midnight saw Agassiz and the writer of this sketch working by the dim light of two tallow candles dissecting the animal, and shipping off its half-cleaned bones to Neuchatel, before he ventured to take the much- needed rest. Subsequently to his first visit to England the labours of Hugh Miller, Dr Malcolmson, and other geologists brought to light the marvellous ichthyal fauna of the Devonian beds of the north-east of Scotland. Murchison and Sedgwick had some time previously directed attention to the existence of fishes of this geological age, especially amongst the bituminous shales of Caithness; but the more recent discoveries were of far greater interest than the earlier ones, because of the strange forms of the Pterich- thys, the Coccosteus, and other species then made known to geologists for the first time. The supposition of Hugh Miller, that some of these fishes had vertical instead of horizontal mouths, suggestive of a transition from the crustacean to the ichthyal type, added fresh interest to the subject in the eyes of a philosophic inquirer like Agassiz. These fossils were reported upon by him more than once, and were finally made the subjects of a special monograph, which was published in 1844. Miller s inter pretation of the structure of the moiith Agassiz soon demonstrated to be erroneous. The year 1840 witnessed the inauguration of a new movement, which has proved to be of the utmost import ance to geological science. Previously to this date De Saussure, Venetz, Charpentier, and others had made the glaciers of the Alps the subjects of special study, and Charpentier had even arrived at the important conclusion that the well-known erratic blocks of alpine rocks scattered so abundantly over the slopes and summits of the Jura mountains, had been conveyed thither by glaciers. The question having attracted the attention of Agassiz, he at once grappled with it in his wontedly enthusiastic manner. He not only made successive journeys to the alpine glaciers in company with Charpentier, but he had a rude hut con structed upon one of the Aar glaciers, which for a time he made his comfortless home, in order that he might the more thoroughly investigate the structure and movements of the ice. These labours resulted in the publication of his magnificent illustrated folio entitled Etudes sur les Glaciers. In this important work the movements of the glaciers, their moraines, their influence in grooving and rounding off the rocks over which they travelled, producing the striations and roches moutonnes with which we are now so familiar, were treated with a comprehensiveness which threw into the shade all the writings of previous labourers in this field. He not only accepted Charpentier s idea that come of the alpine glaciers had extended across the wide plains and valleys drained by the Aar and the Rhone, and thus landed parts of their remains upon the uplands of the Jura/, but he went still further in the same direction. He concluded that, at a period geologically recent, Switzerland had been another Greenland ; that instead of a few glaciers stretching their restricted lines across the areas referred to, one vast sheet of ice, originating in the higher Alps, had extended over the entire valley of north-western Switzer land until it reached the southern slopes of the Jura, which, though they checked and deflected its further extension, did not prevent the ice from reaching in many places the- summit of the range. At a later period we shall find him holding a similar view in the case of the vast plains spread out between the Andes and the eastern coast of South America. The publication of this work gave a fresh impetus to the study of glacial phenomena in all parts of the world. In 1841 Agassiz spent many weeks in his hut on the Lower Aar glacier, where he received as his guest the late Professor James Forbes, who was also engaged upon the study of glacial phenomena. The latter philosopher, in his work on Norway and its Glaciers, recognised in the fullest manner his indebtedness to Agassiz for much new light respecting the details of glacial action. Thus familiarised with the phenomena attendant on the movements of recent glaciers, Agassiz was prepared for a new and most unexpected discovery which he made in 1846, in conjunction with the late Professor Buckland. These two savants visited the mountains of Scotland together, and found in six different localities clear evi dence of some ancient glacial action. The discovery was announced to the Geological Society of London in a joint communication from the two distinguished observers. Similar discoveries were subsequently made by Buckland, Lyell, Ramsay, and others in various parts of Scotland, Westmoreland, Cumberland, and North Wales. The for mer existence of glaciers in each of these mountainous districts is a fact that no one now presumes to doubt any more than that these glaciers, either directly, or indirectly in the shape of icebergs, have at least contributed largely to the accumulation of those wide-spread deposits with which geologists are familiar under the name of drift and boulder formations. But we must now follow Agassiz to a new sphere of labour. In 1838 he was appointed to the professorship of natural history at Neuchatel, with a very limited income. In the autumn of 1846 he crossed the Atlantic, with the two-fold design of investigating the natural history and geology of the United States, and delivering a course of lectures on zoology at the Lowell Institute; and the tempting advantages, pecuniary and scientific, presented to him in the New World, induced him to settle in the United States, where he remained to the end of his life. He was appointed professor of zoology and geology in the university of Cambridge, U.S., in 1847. He left that post in 1851 for a medical professorship of comparative anatomy at Charlestown, but returned in 1853 to Cambridge. This transfer to a new field, and the association with fresh objects of high interest to him, gave his energies a new stimulus. Volume after volume now proceeded from his pen : some of his writings were popular, and ad dressed to the multitude, but most of them dealt with the higher departments of scientific research. His work on Lake Superior, and his four volumes of Contributions to the Natural History of the United States, were of this latter character. But whilst thus working earnestly at American zoology, he still kept in view more generalised inquiries, the fruits of which appeared in 1854, with the title of Zoologie Generale et Esqidsses Generales de Zoologie con- tenant la Structure, le Dbveloppement, la Classification, &c., de tons les Types d Animaux vivants et detruits. Before leaving these literary labours, we must not overlook the valuable service he rendered to science by the formation,
for his own use, of a catalogue of scientific memoirs an
