. Carnegie Institution of Washington publication. BASIDIOBOLUS. 77 wall cutting off a small cell at the end of the beak (Fig. 25, B). The manner in which this wall is laid down is worthy of special notice here, since it is formed as in the higher plants, namely, through the instrumentality of the kinoplasmic connecting fibers, appearing at first as a cell-plate. Apart from Chara this is the only instance as yet known among the lower cryptogams in which a cell-plate is thus formed. Immediately the nuclei have entered the beaks, and prior to the prophase of the nuclear division just mentioned, a
. Carnegie Institution of Washington publication. BASIDIOBOLUS. 77 wall cutting off a small cell at the end of the beak (Fig. 25, B). The manner in which this wall is laid down is worthy of special notice here, since it is formed as in the higher plants, namely, through the instrumentality of the kinoplasmic connecting fibers, appearing at first as a cell-plate. Apart from Chara this is the only instance as yet known among the lower cryptogams in which a cell-plate is thus formed. Immediately the nuclei have entered the beaks, and prior to the prophase of the nuclear division just mentioned, and also before an increase in size of the female gamete, a hole is formed in the transverse wall separating the two gametes. The two daughter nuclei cut off in the ends of the beaks gradually disappear, while the other two pass down deeper into the cytoplasm. FIG. 25.—Formation of gametes in Basidiobolus rantirum Eidam.—(After Fairchild.) A, two gametes showing the beaks; the nuclei, which are in the beaks, are in the resting condition ; the hole has already formed between the gametes. B, the nuclei have divided and two of the daughter nuclei are cut off in the ends of the beaks, while the other two, which have increased in size, have passed down near the opening in the transverse wall; the female gamete has increased greatly in size, the male retaining its former dimensions. of the cells (Fig. 25, B). The male nucleus now passes through this opening and comes in contact with the female nucleus (Fig. 26, C). During these movements the nuclei attain their original size, and each contains one or more interwoven nuclear threads, in which chromatin granules are situated at rather long intervals. In this condition the two nuclei remain some time before fusing. The entire cytoplasm of the two gametes is utilized in the formation of the young zygospore, which now forms about itself a very thin wall, within which the thick endospore, consisting of several layers, is gradually devel
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