Freeze-dehydration for permanent mounts after aceto-orcein stain.
Fresh smears of mammalian material were stained 5 min (only) by La Cour's (1941) aceto-orcein method at 60°C, briefly rinsed and drained, and then dehydrated in a prechilled equal-parts mixture of absolute alcohol and anhydrous acetone held 2 hr or more at — 20°C or lower by means of dry ice. The preparations were differentiated 30 sec at room temperature in 95% alcohol containing 1% HCl, counterstained (optional) in a 0.01% solution of fast green FCF in absolute alcohol for 10 sec, passed through 2 changes of xylene and mounted in HSR or other synthetic resin.
THE IRON-ACETOCARMINE METHOD OF FIXING AND STAINING CHROMOSOMES
A short description of this procedure was given in Vol. 55 of the American Naturalist, pp. 573â€”574. The method has now been used almost daily for five years, and certain improvements have suggested themselves. The solution can be prepared by mixing about equal volumes of glacial acetic acid and water. To this is added powdered carmine in excess. The liquid is then â€ ? just brought to boil, cooled, and decanted. To the red solution there are then added a few drops of a solution of ferric hydrate in 50 per cent. acetic acid, to act as a mordant. The amount of iron varies with different objects. Too much produces a precipitate in a short time. The more
THE GEOLOGICAL SURVEY IN YORKSHIRE
( Presidential Address delivered at Sheffield , 14 th December, 1957).

I. General History For some years after its institution in 1835 the Geological Survey was preoccupied with the south-western parts of Britain, and it was almost mid-century before the work of “making the geological map” was extended northwards to the borders of Yorkshire. Already several one-inch maps had been completed and were issued, hand-coloured, on what later became known as the “Old-Series” grid, and in 1846 De la Beche published his first volume of Memoirs of the Geological Survey. We find the name of Warington W. Smyth on a detailed section, dated 1845, of the first Woodhead Tunnel which lies partly in Yorkshire. And at about the same time William Smith’s nephew, John Phillips, was spending some eight years of his life on the staff of the Geological Survey, bringing to publication in 1852 the first official map to cover a part of Yorkshire—the original edition of the Old-Series sheet 81 NE., mainly covering the High Peak of Derbyshire but including, on its east side, small parts of the Yorkshire Coalfield near Sheffield.

Once started, the survey of Yorkshire continued at such a pace that its completion was announced in 1882. A small band of field geologists of outstanding ability was responsible for this feat: W. W. Smyth, A. H. Green, C. le Neve Foster, Clifton Ward and J. R. Dakyns who, with John Phillips, brought the survey of the Sheffield area, Sheet 82 NW., to its publication in 1867; W …