. Fecundation in plants. Plant embryology; Plants, Sex in; Karyokinesis. 130 ARCHEGONIATES. cytoplasm along whose outer edge is a delicate thread or band derived also from the cytoplasm, and from which the cilia are developed (Fig. 52, A). Belajeff was the first to call attention to the cilia-bearing band, which he observed in the development of the spermatozoid in a fern and in Equisetum. He also reported a similar body in Chara. In speaking of the body which gives rise to the cilia-bearing band, Belajeff used the term "Nebenkern," because of its apparent resem- blance to a body of
. Fecundation in plants. Plant embryology; Plants, Sex in; Karyokinesis. 130 ARCHEGONIATES. cytoplasm along whose outer edge is a delicate thread or band derived also from the cytoplasm, and from which the cilia are developed (Fig. 52, A). Belajeff was the first to call attention to the cilia-bearing band, which he observed in the development of the spermatozoid in a fern and in Equisetum. He also reported a similar body in Chara. In speaking of the body which gives rise to the cilia-bearing band, Belajeff used the term "Nebenkern," because of its apparent resem- blance to a body of that nature in the spermatid of certain animals. In 1897 Webber described the development of the cilia-bearer in the spermatozoid mother-cell of Zamia, and gave to it the name blefh-. FiG. SI.—Development of sperma- tozoid in Gymnografnme sul- fhuTea.—( Belajeff.) A, grandmother-cell of spermatozoid with two primordia of bleph- aroplasts. B, two spermatozoid mother-cells, each with its blepharoplut primordium. C, spermatozoid mother-cell rounded off. T>, the young; blepharoplast has begun to elongate. E, stage a little older than D. F, blepharoplast much elongated; its anterior end extends out to plasma membrane. G, transformation of nucleus has begun; it is somewhat pear- shaped, being concave on side turned from blepharoplast; end which will be anterior in mature sperm is pointed, H, later stage; cilia have been developed from the blepharoplast. aroflast.^ Ikeno and Hirase, who were the first to discover the spermatozoid in certain gymnosperms, described the development of the cilia-bearing band in the spernfatozoid of Cycas and Ginkgo. Belajeff and the two Japanese investigators consider the body developing into the blepharoplast as a centrosome. The author is convinced that it has been clearly proved that the blepharoplast is not a centrosome, nor, as yet, has any phylogenetic relationship been shown to exist between the blepharoplast and the centrosome as we k
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