At a slightly later stage, in the place of the original germinal vesicle there may be observed in the fresh ovum two clear spaces (fig. 24), one ovoid and nearer the surface, and the second more irregular in form and situated rather deeper in the vitellus. In the upper space parallel striæ may be observed. By treatment with reagents the first clear space is found to be formed of a horizontally-placed spindle with two terminal stars, near which irregular remains of the germinal spot may be seen. Slightly later (fig. 25) there may be seen on the lower side of the spindle a somewhat irregular body, which may possibly be part of the remains of the germinal spot, though Fol holds that it is probably part of the membrane of the germinal vesicle. The lower clear space visible in the fresh ovum now contains a round body, fig. 25. Fol concludes that the spindle is formed out of part of the germinal vesicle and not from the germinal spot, while he sees in the round body present in the lower of the two clear spaces the metamorphosed germinal spot. He will not, however, assert that no fragment of the germinal spot enters into the formation of the spindle. [FIG. 25. OVUM OF ASTERIAS GLACIALIS, AT THE SAME STAGE AS FIG. 24, TREATED WITH PICRIC ACID (copied from Fol).] The following is Hertwig's (No. 92) account of the changes in the germinal vesicle in Asteracanthion. Shortly after the egg is laid the protoplasm on the side of the germinal vesicle towards the surface of the egg develops a prominence which presses inwards the wall of the vesicle. At the same time the germinal spot develops a large vacuole, in the interior of which is a body consisting of nuclear substance, and formed of a firmer and more refractive material than the remainder of the germinal spot. In the prominence first mentioned as projecting inwards towards the germinal vesicle first one star, formed by radial striæ of protoplasm, and then a second make their appearance; while the germinal spot appears to have vanished, the outline of the germinal vesicle to have become indistinct, and its contents to have mingled with the surrounding protoplasm. Treatment with reagents demonstrates that in the process of disappearance of the germinal spot the nuclear mass in its vacuole forms a rod-like body, the free end of which is situated between the two stars which occupy the prominence indenting the germinal vesicle. At a later period granules may be seen at the end of the rod and finally the rod itself vanishes. After these changes by the aid of reagents there may be demonstrated a spindle between the two stars, which Hertwig believes to grow in size as the last remnants of the germinal spot gradually vanish, and he maintains that the spindle is formed at the expense of the germinal spot. The stage with this spindle corresponds with fig. 25.