time, being Grey Crows, Carrion Crows, Starlings, Skylarks, Chaffinches, and Tree Sparrows.

Mr. Caton Haigh, who is favourably situated on the north coast of Lincolnshire for observing these immigrants, remarks that the parties sometimes consist entirely of old birds; sometimes of old and young, and sometimes, so far as he was able to determine, wholly of young birds.

Autumn Immigration from North-Western Europe. The immigration from Northern Europe is far from being extensive. Rooks from Scandinavia1 appear in the Shetlands and at some of the Orkneys (North Ronaldshay in particular) from the middle of October to mid-November. They arrive during the night, sometimes in fairly large flocks, and often remain for a short period before proceeding southwards."

On the east coast of the mainland of Great Britain the arrival of these northern immigrants does not seem to have been observed; but passage movements southwards performed during the daytime are recorded as far south as Flamborough Head. Similar migrations are witnessed on the west coast of Scotland, chiefly at the Hebridean stations, which likewise follow the arrivals from the north. These diurnal migrations are probably passage movements to British winter quarters, and they sometimes extend as far westward as the Flannan and Monach Isles. The Rook is a winter visitor to Barra and probably to some other of the Hebrides.

The autumn immigrants from both east and north settle down for the winter in Great Britain-chiefly, I believe, in eastern England and do not, as far as we know at present, proceed southwards of the British area after arrival on our shores.

Autumn Emigration from Britain.-At the Goodwin Lightships, on several occasions during September and October,3 Rooks, sometimes in considerable numbers, are recorded as crossing the Straits of Dover in the daytime, in an easterly and south easterly direction, as if proceeding to the coasts of Belgium and France. These records are of considerable interest when considered in connection with the more regularly observed return movement which occurs in the spring. The early date on which some of these migrations are chronicled would seem to indicate that the emigrants are British birds, for they are dated prior to the arrival of the earliest autumn visitors from the Continent.

4

Spring Immigration to Britain.-During late February, throughout March, and sometimes in the first half of April, considerable numbers of Rooks, occasionally accompanied by Daws, Starlings, and Skylarks, arrive during the daytime on the south-east coast of England between Norfolk and Kent, the immigrations on some occasions lasting for several successive days."

Professor Collett informs me that the Rook, which is not an abundant species in Norway, mostly leaves that country for the winter.

2 Mr. Thomas Henderson, junior, of Dunrossness, tells me that during long-continued southerly gales he has often seen the immigrant Rooks rise in a flock to a considerable height, as if anxious to be off, and then settle down again. They leave Shetland for the south as soon as favourable conditions set in.

The earliest of these autumn departures is dated September 9, and the latest October 30.

The earliest record is for February 23, and the latest for April 18.

The late Sir Edward Newton made a number of interesting observations on these movements as witnessed by him at Lowestoft. He writes thus on one of them which occurred on March 31, 1889: This morning, while sitting in the house, I heard Rooks and Jackdaws. On looking out I saw flocks of about one hundred coming in very high from the S.E. A few minutes later I again heard Rooks and

These, or perhaps we should say some of them, are, no doubt, the return movements to British haunts of the emigrants observed leaving our shores in the autumn. Other individuals, especially the late arrivals, may be on passage to the Continent, the corresponding autumn passage southwards on the part of foreign immigrants is not obviously recorded in our data, though it possibly occurs.

Spring Emigration to Central Europe.-As the reverse migration was the main one of the autumn, so is this the most important one of the spring.

The first departures of the Rooks which have wintered in England are those for Central Europe. As early as the second week of February (the 10th being the earliest record) these great emigrations eastwards set in, reach their maximum during March, and are much in evidence until the middle of April, the 23rd of that month marking their extreme limit in the observations. During this prolonged period vast numbers of emigrants are observed at the lightships between the Humber and the mouth of the Thames (occasionally at the Straits of Dover), passing to the south-east and east during the daytime, from 6 A.M. onwards, and sometimes flying very high; Grey Crows, Daws, Skylarks, Tree Sparrows, and Chaffinches not unfrequently departing at the same time.

Prior to their departure certain of these emigrants have been observed passing southwards, occasionally accompanied by Grey Crows, on both the Yorkshire and Norfolk coasts, en route for some particular points of embarkation for the crossing of the North Sea.'

Spring Emigration to North-Western Europe.-The Rooks from Scandinavia which have wintered in our islands return north in March and April, and (as in the autumn) are mainly observed on passage in the Orkneys and Shetlands. Some appear in these northern islands as early as the first days of March, but the chief movements take place during its latter days and the early days of April, though a few are seen as late as the end of that month. They arrive during the night, occasionally in large flocks, and are sometimes accompanied by Grey Crows and Daws. The emigrants appear at stations widely scattered over both Orkney and Shetland, and usually tarry for a few days before proceeding northwards.

There are only a few records relating to these movements northwards on the east coast of Britain, and it would seem as if they but rarely came under notice at any of the mainland stations. Rooks in small numbers are, however, observed annually at the Hebrides, including the Flannan Isles, on passage during March and April. They occur at the Færoes on passage about the same time (Andersen), and arrive in Norway during the latter part of March or beginning of April (Collett).

Irish Migrations.-The regular migrations of the Rook witnessed in Ireland are of an extremely limited nature, and relate to certain arrivals in the spring. Ireland does not appear to be visited by Continental birds as a winter resort, and hence the movements observed there are chiefly

Jackdaws, and again saw another flock, also very high, flying northwards; they were occasionally toying and circling as one sees them in summer and autumn.'

At Somerton, on the Norfolk coast, on March 20, 1886, Rooks were flying due south in a continuous stream from 10.30 A.M. to 6 P.M., never fewer than 1,000 being in sight at the same time. (Report, 1885, p. 47.)

2 Stragglers have been observed as late as May 16, and some of a party which arrived in Unst on March 4, 1901, remained until July 23 (T. E. Saxby), and probably did not proceed beyond the limits of the British Isles.

of a local or irregular character. There are, however, occasional intermigrations with Great Britain.

Irish Autumn Movements.-During October and November in some years Rooks have been recorded as arriving on the south-east coast, but these immigrations are so irregular and unimportant as not to merit further notice at present. Such passages on the part of other species are among the best observed and most interesting of the Irish movements, and the absence of the Rook presents a remarkable negative feature, especially so since nearly all the species from Central Europe which winter in England find their way to Ireland by this route in considerable numbers.

Rooks have also been occasionally observed in October at the islands (Rathlin and Maidens) off the north-east coast, coming from the direction of the mainland of Scotland, and sometimes 'rushes' are recorded.

Irish Spring Movements.-The chief feature in the migrations of the Rook as observed in Ireland is the regular spring immigration observed (during the daytime) on the south-east coast, between the latter half of March and the third week of April-the movements indicating that a corresponding autumn emigration most likely takes place, though such has, as yet, entirely escaped notice. It is impossible to determine the precise nature of these movements. They may relate to birds returning to their native homes, or to birds of passage traversing the Irish coast on their way northwards. We have, however, no further information concerning them, and the question must remain open.

There are occasional records of spring departures. These are witnessed at Copeland Island, Rathlin, and the Maidens, off the north-east coast, where occasionally Rooks have been observed moving towards Scotland in April. These are probably return migrations of the birds sometimes observed at the same stations moving in an opposite direction in the autumn.

Apparently Erratic Movements to the West.-In the late autumn large numbers of Rooks have occasionally been observed moving westwards beyond the British Isles and over the waters of the Atlantic, wherein many perish, and whence others, having retraced their flight, arrive in an exhausted condition on our furthest western shores.

Perhaps the best instance on record of such movements occurred in October 1893, when late in the month vast numbers (estimated at from 5,000 to 6,000) arrived at Scilly from the south-east, accompanied by a few Daws, and proceeded in a westerly direction. About the same time a large flight of Rooks, presumably the same birds, were met with by steamers out in the Atlantic some 300 miles west of Ireland, and in such an exhausted condition that some fell into the sea and were drowned, being too weak to retain their foothold on the vessel on which they had alighted. It is said that these birds avoided the outward-bound steamers, but sought those which were approaching the land. As there was nothing unusual in the weather at the time of the birds' appearance in Scilly, they were certainly not on this occasion blown out to sea, a theory which has been advanced to explain similar flights.

Return movements of considerable numbers of Rooks from the Atlantic have several times been recorded at stations on the west coast of Ireland. In 1884, between November 2 and 25, large numbers

J. H. Jenkinson, The Field, March 3, 1894.

arrived at Tearaght Island and at the Skelligs, off the coast of Kerry, for several days, either in flocks or at intervals.

Again in 1887, between October 21 and November 23, they appeared at the same stations, also in numbers and direct from the Atlantic. Similar movements were witnessed in 1888 and 1890, chiefly in November, at Tearaght and at Slyne Head, Galway.

In the middle of November 1893 (soon after the great movement observed at Scilly), some 4,000 or 5,000 appeared in the Island of Lewis, arriving in an exhausted state, and great numbers were washed ashore on the west side of the island.' It is worthy of remark that actual occupancy of a new 'Rookery' took place within the castle grounds of Stornoway, Lewis, very shortly after this phenomenal invasion was first recorded in The Field by Mr. Duncan Mackenzie.2

Summary of the Migrations of the Rook.-1. Partial and irregular movements on the part of young and old begin at the close of the nesting season and continue throughout the autumn.

2. Vast numbers of Rooks from Central Europe arrive on the southeast coast of England (coming from the east and south-east) between the latter half of September and the middle of November, to pass the winter in the eastern counties of England. This is the main autumnal move

ment.

3. From the middle of October to the middle of November emigrants from Scandinavia arrive on our northern shores and remain to winter in Great Britain. They are chiefly observed as immigrants in Shetland and Orkney, and, on passage to their British retreats, on the north-east and north-west coastlines.

4. In severe winters some emigrate from the mainland of North Britain and are observed in small numbers in the Western Isles (Lewis &c.)

5. Late in February, during March, and sometimes early in April numbers of Rooks arrive on the south-east coast of England from the Continent, moving in a westerly and north-westerly direction during the daytime. These are most probably returning British emigrants whose departure in the autumn has escaped notice.

6. Early in February and until mid-April the Rooks from Central Europe which have wintered in England depart from the south-east coast for their summer homes. This is the most important movement of the spring.

7. Throughout March and April the winter visitors to Britain from Scandinavia are observed, chiefly at the Orkneys and Shetlands, returning to their northern summer quarters.

8. The Irish movements are chiefly of an irregular and unimportant nature, and Ireland is not resorted to by the Continental visitors for winter quarters. In October and November in some years arrivals have been recorded on the south-east coast after passage across St. George's Channel; and there are occasional arrivals from Scotland at the islands off the N.E. coast. In spring there is a regular return migration witnessed on the S. E. coast between the latter half of March and the third week of April; implying an unobserved autumn emigration either of

1 D. Mackenzie, The Field, April 4, 1894.
2 Annals of Scot. Nat. Hist., pp. 149-150.

native Rooks or of birds of passage, or both. There are a few records of the return of Rooks to Scotland in the spring.

9. In the autumn of some years apparently erratic movements westwards over the Atlantic have taken place. During these many of the wanderers have been known to perish, while others have been observed returning, in an exhausted condition, on the west coast of Ireland, and of the Hebrides.

The State of Solution of Proteids.-Report of the Committee, consisting of Professor HALLIBURTON (Chairman), Professor WAYMOUTH REID (Secretary), and Professor E. A. SCHÄFER, appointed to investigate the state of Solution of Proteids.

THE test of solution employed in this research has been the production of a lasting osmotic pressure upon a membrane impermeable to the proteid when the pure solvent is exhibited on one side and the reputed solution on the other side of the membrane. A positive result by direct manometric observation is taken as indicating a condition of true solution, a negative result as indicative of a state of fine suspension of the proteid. The membrane used has been almost exclusively formalised gelatine supported in the pores of peritoneal membrane, fixed on a perforated metal support, and set in an osmometer in which continuous stirring for periods of six to eighteen days was possible.

The pressures were read daily with careful thermometric correction. Ovalbumin, serum-albumin, and various globulins have chiefly been used for experiment, though work with other proteids is still in progress.

Since the molecular weights of proteids is uncertain, the results have been simply stated in the pressures in mm. of mercury for 1 per cent. concentration of the proteid in reputed solution as determined by analysis.

As the source from which all proteids are drawn must, by the nature of the case, be one heavily contaminated with other bodies, and as it is well known that proteids absorb other bodies in solution very strongly, attention has been largely directed to the purification of the material used for experiment. In some cases crystallisation may assist, but it is believed that thorough washing with salt solutions in which the crystallised or precipitated proteid is insoluble, is the best means for removal of adherent foreign substances. The purification of the material for experiment has been the most laborious part of the research.

The fact that solutions of similarly prepared samples of the same proteid (say ovalbumin) obtained from different sources (different batches of eggs) may give very different osmotic pressures per unit concentration of proteid, suggested that the pressure read in such cases is not due to the proteid in solution, but to some other body or bodies in true solution and present in variable amount.

If this is so, thorough washing of all such proteids, which in apparent solution at first give an osmotic pressure, should finally yield a fluid holding proteid, but giving no osmotic pressure.

This has been amply verified in the experiments, both in the case of ovalbumin and serum-albumin, and osmotic-pressure-free proteid 'solutions' have been prepared without great difficulty, and the proteid obtained dry by the vacuum pan for use in other experiments.