. The cell; outlines of general anatomy and physiology. le for observation. Later on, thin layers of fibrin, pro-duced by coagulation, are deposited upon the disc of elder pith ;these may be removed, and, with the cell elements which areattached to them, may be easily examined. Ranvier (VI. 5-1) observed all the phenomena of division take 208 THE CELL place in a lymph cell during the course of three hours, the pre-paration being kept at a temperature varying from 16° to 18°.Arnold (VI. 1) and others have verified his statements, and haveamplified them in various ways. The vesicular nucleus can
. The cell; outlines of general anatomy and physiology. le for observation. Later on, thin layers of fibrin, pro-duced by coagulation, are deposited upon the disc of elder pith ;these may be removed, and, with the cell elements which areattached to them, may be easily examined. Ranvier (VI. 5-1) observed all the phenomena of division take 208 THE CELL place in a lymph cell during the course of three hours, the pre-paration being kept at a temperature varying from 16° to 18°.Arnold (VI. 1) and others have verified his statements, and haveamplified them in various ways. The vesicular nucleus can changeits form actively, and can cover itself with excrescences and pro-tuberances. Under such circumstances constrictions frequentlyoccur, after which the nuclei break up into two, three, or morepieces (Fig. 100 A, B). The nuclear fragments move apartfrom one another, not infrequently remaining joined together fora considerable time by delicate connecting threads. Cell divisionoften closely follows nuclear division, as is seen in Figs. 100 A, B. B. AS&L m ^•;i-?---- \ Fig. 100.—A A migratory cell from a disc of elder pith which has lain for ten days inthe lymph sac of a Frog. When first observed the nucleus was somewhat constricted inits middle, whilst its ends were bilobed. After five minutes the nuclear division was com-pleted (after Arnold, PI. XII., Fig-. 1). B Migratory cell during division. Fig. A de-veloped into Fig. B during the course of thirty minutes (after Arnold, PI. XII., Fig. 3). The protoplasmic body also becomes constricted between thenuclear fragments, which move apart, but are still joined by afine thread. The two nuclear fragments move in opposite direc-tions by means of a large number of amoeboid processes. Inconsequence, the connecting bridge between them is sometimesdrawn out to a long fine thread, after the daughter-nuclei haveseparated from one another. No law can be laid down as to the time when the variousstages of division follow one another
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