I4 6 BOTANICAL GAZETTE [march 



Most of the papers concerning spermatogenesis in pteridophytes 

 were published after the appearance of Schmitz's study of Chara> 

 by such investigators as Carnoy (16, in Hymenophyllum), Belajeff 

 (i, in Isoetes; 2,4, in Gymnogramme and Equisetum), Zacharias 

 (102, in Pteris), Campbell (12, in Onoclea, Asplenium, Gymno- 

 gramme, Adiantum, Alsophila, and Ceratopteris; 13, in Pilularia; 

 14, in Osmunda), Buchtien (10, in Equisetum), Leclerc du Sablon 

 (61, in Cheilanthes), Guignard (31, 32, in Angiopteris, Pilularia, 

 and Equisetum), Schottlander (78, in Gymnogramme), and 

 Strasburger (85, in Marsilia). 



These studies begin with the structure of spermatids and are 

 chiefly devoted to details of the events which occur within the sper- 

 matids during their transformation into sperms. Since the forms 

 investigated were different, it is natural that the results should diverge 

 in some particulars; but so far as the constituents of the mature 

 sperm are concerned, the views fall into two categories. One group 

 of authors, as Zacharias, Leclerc du Sablon, and Belajeff, be- 

 lieves that the spiral body of the sperm consists of a nucleus always 

 enveloped by a layer of cytoplasm, which becomes the main constituent 

 of the anterior coiled part of the body where cilia are produced; 

 nuclear material docs not extend to the anterior part. The other 

 authors mentioned above hold that the nucleus is the main constituent 

 of the body of the sperm, its anterior coiled part being enveloped with 

 cytoplasm on which cilia are borne. Most observers of both groups 

 agree that the cilia are produced from the cytoplasm, and that the 

 vesicle (Blase) which is attached at the posterior end of the sperm 

 is cytoplasmic in nature. 



Most of the investigation of the origin and nature of the cilia- 

 bearing organs of the sperms of pteridophytes has been done since 

 the discovery of motile sperms and cilia-bearing structure in gymno- 

 sperms was made by Ikeno (40, 41, 42, 43), Hirase (36, 37), and 

 Webber (94, 95). The first paper that dealt with the details of 

 the origin of cilia-bearing structures in the sperms of pteridophytes 

 was that of Belajeff. Following his three preliminary notes (3,4, 

 5), he published in 1898 an account (6) of spermatogenesis in Gymno- 

 gramme and Equisetum. Two deeply staining bodies (which he 

 called Nebenkern) appeared on opposite sides of the nucleus previous 



