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.
Mitotic Mechanisms of Normal and Malignant Cells: (with Plate XXII)
RESUMEL'auteur de cet article poursuit une discussion detaillee des diverses aberrations de nombres chromosomiques, qui pourraient etre dues soit a l'endomitose, soit a la pseudo-meiose somatique, soit enfin a la symploidie et a la dysploidie. Il propose ces deux derniers mots comme termes nouveaux pour signifier, respectivement, la conjugaison dans les tissus de deux cellules non-sexuelles voisines, souvent jumelles, et la « normalisation » d'une cellule cancereuse polyploide a noyau geant se divisant par karyokinese en plusieurs (au lieu de deux) cellules-filles a taux de chromosomes inferieurs.
XV. Notes on the Geological Survey Memoir—“The Geology of the Glasgow District.”
Introductory. During the late summer the Geological Survey issued a map of the Glasgow district which will prove a boon not only to the members of this Society, but also to the increasing number of those who, although not members, still take an interest in geology as a branch of liberal education. The present map differs from its predecessors in that it is colour-printed, and the printing and general details are brought out more clearly than was possible in the hand-coloured maps. This fact has been taken advantage of to add an enormous amount of detail, which is often of such a minute character that after study one feels inclined to wish that he were gifted with microscopic eyes or that the map had been drawn to a larger scale. Not the least of its benefits is the low price at which it is sold (2s. on paper, and 3s. on cloth), the price of the previous maps having lately become prohibitive (19s. 3d. on paper). It will be observed that the long way of the map is from north to south. This has doubtless been adopted for good and sufficient reasons, if we only knew them; but I, at least, would have preferred that the long way should have been east and west, with Glasgow in the centre. The map is accompanied by an extensive memoir of the geology of the district, and the more one reads of it the more one is impressed with the This 250-word extract was created in the absence of an abstract