Mnium affine , var. ciliaris ( Grev.), C.M. 
455 
EXPLANATION OF FIGURES IN PLATE XXI. 
Illustrating Mr. Woodbunfls paper on Spermatogenesis in Mnium affine, var. ciliaris (Grev.), C.M. 
The figures were drawn at table level with the aid of a camera lucida, a Spencer apochromatic 
immersion lens 1*5 mm. N.A. 1*30, and compensating ocular No. 12, giving a magnification of 
approximately 3,200 diameters. 
Fig. 1. Androgone or cell from the spermatogenous tissue of a young antheridium, in a resting 
stage. 
Fig. 2. Nucleus, from an older antheridium, entering upon the prophase of division. 
Fig. 3. Cell from the same antheridium as Fig. 2, showing the collection of the chromatin into 
large lumps preparatory to spireme formation, and the nucleolus growing less in staining capacity. 
Fig. 4. Spireme in a cell of the same group as Figs. 2 and 3. Probably just previous to the 
last antheridial division. 
Fig. 4 a. Spireme segmented into six chromosomes, which seems to be the gametophytic 
number for Mnium affine , var. ciliaris. 
Fig. 4 b. Late anaphase. 
Fig. 5. Telophase of division immediately following Fig. 4. 
Fig. 6. Later telophase and formation of cell-plate. 
Fig. 7. Early stage of androcyte. Cytoplasm somewhat flocculent and slightly lumpy. 
Fig. 8. Practically the same stage as Fig. 7, but showing more distinctly the chromatin 
network and the nucleolus. 
Fig. 9. Also early stage of androcyte, showing nucleolus and the chromatin scarcely out of the 
spireme stage. About the same stage as Figs. 7 and 8. 
Fig. 10. Androcyte with nucleus showing a nucleolus and chromatin network. A globular 
dark staining body, the blepharoplast, is present in the cytoplasm and the nucleus has shifted to one 
side of the cell. 
Fig. 11. Androcyte with the nucleus containing a delicate chromatin network. The blepharo¬ 
plast is considerably elongated. 
Fig. 12. A little more advanced than Fig. 11. The nuclear content is becoming homogeneous, 
and the blepharoplast is growing in length. 
Fig. 13. Blepharoplast extending at least half-way around the cell. The nucleus has become 
quite crescent-shaped, and a number of densely staining bodies are present in the cytoplasm. 
Fig. 14. Blepharoplast still elongating and the nucleus being distributed along its course. 
A vacuole is present in the cytoplasm. 
Fig. 15. Somewhat more advanced than Fig. 14, the blepharoplast being distinguishable 
only at the posterior end of the sperm. Indications of a vacuole similar to the one in Fig. 14. 
Fig. 16. Sperm of about the same stage of development as shown in Fig. 15, but indicating 
much more rapid development. A vacuole is present in the cytoplasm, but the nucleus and 
blepharoplast seem indistinguishable. 
Fig. 17. Approximately the stage as shown in Fig. 12, but viewed from the back (Fig. 12 may 
be considered a side-view). The blepharoplast is seen to be a flat band. 
Fig. 18. From the same point of view as Fig. 17, showing only the surface. The blepharoplast 
appears to be darker along one edge. 
Fig. 19. Cross-section through such a cell as shown in Figs. 16, 21, 22, or 23. The coiled 
portion of the sperm, now consisting of nucleus and blepharoplast, is seen cut in cross-section 
four times. 
Fig. 20. Coiled portion of the sperm cut in cross-section twice. The vacuole noted elsewhere 
is present. 
Fig. 21. Sperm allowed to escape and killed with 2 % osmic acid. A densely staining cord, 
evidently the blepharoplast, extends throughout the length of the sperm. The nucleus is well 
distributed along the blepharoplast. A vesicle is contained in the cytoplasmic region and cilia are 
present. 
