276 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VOL. V- 



I, always on the crest of the antheridial ridge, figure 23. The older 

 antheridia are found generally higher on the ridge than the younger ones, 

 figure 23, a', a-, a^. The first indication of the male organ is a richly 

 protoplasmic superficial cell, which divides transversely, giving rise to a 

 shallow outer cell and a deep inner one, figure 23 a'. The former 

 becomes transformed into the outer wall of the antheridium, and the 

 latter originates by repeated divisions, the mother-cells of the anthero- 

 zoids. In figure 24 is represented a young stage in which both the inner 

 and outer cells have already undergone several divisions. When the 

 antheridiuni attains about a third of its ultimate size, its outer wall is 

 doubled by periclinal divisions. In figure 25 these are represented as 

 just beginning. Subsequently, the mass of spermatocytes is shut off 

 internally from the prothallium cells by further periclinal divisions, figure 

 23, a^, <Tv. Often the antheridia are accompanied by short multicellular 

 hairs, resembling those found on the rest of the surface of the prothallus 

 and comparable to the paraphyses described by Treub in Lycopodium 

 phleginaria, figure 26, par. The more primitive mother-cells of the 

 antherozoids possess large nuclei with numerous nucleoli, figure 2^, a. 

 After a number of simultaneous divisions of the spermatogenic tissue, 

 the definite spermatocytes are formed. In these the reserve chromatin 

 in the form of nucleoli has disappeared. The filar chromatin is arranged 

 in \vhat appears to be a true reticulum. When the formation of the 

 antherozoids begins, the nucleus contracts somewhat and the bars of the 

 chromatic reticulum become thickened, figure 27 b. The nucleus then 

 assumes a lateral position, and begins to flatten out, figure ij c. This 

 process is continued, and by the lengthening out of the nucleus, the 

 condensation of its chromatin, and the curvature produced by its position 

 in the cell, the antherozoid is formed, figure 27 d. The interesting 

 structure to which Webber'^ in his recent studies on the antherozoids of 

 the Cycadece, has applied the name blepharoplast, and which he compares 

 with the cilia-forming body lately discovered by Belajeff'^ in the 

 FilicinecB and Equisettnece has been looked for in the developing anthero- 

 zoids of Botrycliium virginianum, but has not been made out. This 

 is probably due to the fact that osmic acid fluids could not be used as 

 fixing reagents on account of the oil in the tissues, and because the stains 

 employed were not those used by Belajefif, but either a combination of 

 alum-cochineal and eosin, or aqueous saffranin alone. The material 

 illustrative of spermatogenesis was somewhat limited in amount, and it 

 was not thought advi.sable to risk the series by removing their covers 



i6. Bot. Gazette. Vol. xxiv., p. 253. 



17. Ueber Nebenkern in Spermatog-. Zellen u. d. Sperniatogenese d. Farnkrautern. Berichte d. 

 deutsch. Bot. Gesell. Bd. XV , pp. 337-339. Idem— Die Spermatogenese d. Schachtelhalm. Ibid. Bd. xv. 

 PP- .S39-342- 



