. The cell; outlines of general anatomy and physiology. observations made by Hermann,which have been already mentioned, are especially convincingconcerning the undivided condition of the spindle ; they callto mind my description and representation of the formation ofthe spindle in the germinal vesicle of Asteracantliion (VI. 30a,PL VIII., Figs. 3, 4). In both cases a very small, undividedspindle may be observed between the poles, which are situatednear to one another (Fig. 96), at that period when the nuclearsegments are a good wayoff, and so cannot hide itat all ; it is seen to growgradually,
. The cell; outlines of general anatomy and physiology. observations made by Hermann,which have been already mentioned, are especially convincingconcerning the undivided condition of the spindle ; they callto mind my description and representation of the formation ofthe spindle in the germinal vesicle of Asteracantliion (VI. 30a,PL VIII., Figs. 3, 4). In both cases a very small, undividedspindle may be observed between the poles, which are situatednear to one another (Fig. 96), at that period when the nuclearsegments are a good wayoff, and so cannot hide itat all ; it is seen to growgradually, as its fibrils in-crease in length, until itreaches its full size. The explanation of thisdiscrepancy, as has beensuggested by Hermann, isthat the structure describedby van Beneden and Boveri as the half-Spindle is some- Fig. 96. —Nucleus of a sperm-mother-cell of thing quite different from Salamandra maculate preparing to divide. Posi- ° tion of the spindle between the two centrosomes. the spindle of the earlier (After Hermann, PI. XXXL, Fig. 7.). 202 THE CELL observers. The half-spindles, described by van Beneden andBoveri, consist of a portion of the protoplasmic radiation figureproceeding from the poles, namely, all those fibrils which aresituated in the equator around the nuclear segments. The truespindle lies in the centre of these protoplasmic fibrils and nuclearsegments. Hermann, to distinguish it from van Benedensspindle, has given it the name of central spindle. The prefix central, however, appears to me to be quite superfluous ; forone thing, it is better to decide to limit the name of spindle oncefor all to this portion of the nuclear figure, and to give, ifnecessary, some other name to the protoplasmic polar rays, whichare connected with the nuclear segments, and which are describedby van Beneden and Boveri as half-spindles ; indeed, the namespindle is not suitable to them. Another moot point is the derivation of the spindle investigators are incli
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