. The American journal of anatomy . ng a syncytium. The other striking property possessed by the nuclear areas,which has been observed in the living larva, is that of mitoticdivision. Here, as in the case of the mesenchyme cells describedabove, the picture was unmistakable (fig. 17). The granulesdisappear, as the central portion becomes clear and spindle-shaped. As in the dividing mesenchyme cells spireme formation,arrangement of chrosomes, formation of daughter nuclei, and thecutting apart of the remainder of the cell are to be seen with sur-prising clearness. The chromosomes separate so rapi
. The American journal of anatomy . ng a syncytium. The other striking property possessed by the nuclear areas,which has been observed in the living larva, is that of mitoticdivision. Here, as in the case of the mesenchyme cells describedabove, the picture was unmistakable (fig. 17). The granulesdisappear, as the central portion becomes clear and spindle-shaped. As in the dividing mesenchyme cells spireme formation,arrangement of chrosomes, formation of daughter nuclei, and thecutting apart of the remainder of the cell are to be seen with sur-prising clearness. The chromosomes separate so rapidly thatthe actual movement may be seen. The cutting-in of the cellalso takes place rapidly—from one to two minutes only beingconsumed. After division the two daughter nuclear areas moveapart and maintain for a time a characteristic shape. Later 6 E. R. Clark, An examination of methods used in the study of the developmentof the lymphatic system, Anatomical Record, vol. 5, no. S, 1911, p. 403, fig. 1,and p. 406. 376 ELIOT R. CLARK. Fig. 16 Successive drawings of the same growing lymphatic sprout in thedorsal fin expansion of the tail of a hyla pickeringii larva, to show the move-ments of the nuclear areas. Each of the numbers, 1 to 7, indicates the samenuclear area, which is dotted, in successive observations. In case of the divisionof a nucleus, the daughter areas are indicated as la and lh. Enlarged 180 times. GROWING LYMPHATICS AND THE MESENCHYME 377
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1912
