Fig. 10.—A group of four cells in metaphase of second maturation division. At (h) upper, a centiomere. to the left of which is the oblique section of the spindle fibre tube. At (p) lower left the spindle fibre tube (p) is cut longitudinally. At (p) right a part of the astral fibres are cut across. The mitochondria (m) become scattered during meiotic divisions (Compare with Text-figs. 15 and 16.) Fig. 11—Neck of protoplasm (k) by which all sister spermatic cells are attached to the non-nucleated central mass, partly cut on left. This mass contains fat etc. and mitochondria (m). An unspent acrosome carrier on right containing the acrosome (a). Two flagella (f) cut across showing internal fibres nine peripheral and one central.