Alien.— The Spermatogenesis of Polytrichum juniperinum. 291 
Fig. 28. Beginning of the elongation of the nucleus; the apical body and limosphere are 
connected by a cytoplasmic strand. 
Fig. 29. Different view of an androcyte at about the same stage as that shown in Fig. 28 ; 
part of one cilium is visible. 
Figs. 30-6. Stages in the elongation of the nucleus ; the limosphere is in contact with the 
posterior part of the nucleus. Except in Figs. 34 and 36, the percnosome appears as a compara- 
tively large body. 
Figs. 37-41. Further stages in the elongation of the nucleus; the conspicuous cytoplasmic 
granule appearing in Figs. 37-9 is probably the percnosome. 
Fig. 42. The nucleus has taken on an unusual form, having pushed out two long beaks, one 
anteriorly and one posteriorly. A part of one cilium appears. 
Figs. 43-7. Still further stages in the extension of the nucleus. A portion of the nucleus, 
near its posterior end, is still comparatively thick. The androcyte' shown in Fig. 45, like that in 
Fig. 41, lies in a vesicle which is bounded by what looks like a definite membrane. 
Figs. 48, 49. The nucleus has reached substantially its final length and, by a diminution in its 
volume, is becoming slender throughout. A vacuole is present in the cytoplasm, as also in Figs. 46 
and 47 ; in this vacuole lies a granule, perhaps the percnosome. 
Fig. 50. Two nearly mature androcytes seen in section ; the cilia are conspicuous, and some of 
the cytoplasm remains, though its volume is much reduced, the cell as a whole being lenticular. 
Each androcyte lies in a vesicle bounded by a membrane. 
Fig. 51, 52. Still older androcytes; the cytoplasm is now in two masses, one attached to the 
anterior, the other to the posterior, portion of the body of the antherozoid. 
Fig* 53* The posterior end of the body of an antherozoid at the stage of Figs. 51 and 52, 
showing the posterior cytoplasmic mass, including the limosphere. 
Figs. 54, 55. Antherozoids from sections of mature or nearly mature antheridia. In the 
antheridium from which Fig. 55 was drawn, the intervesicular substance is stained, but no definite 
vesicular membrane is visible. In the antheridium from which Fig. 54 was made, the inter- 
vesicular substance was so faintly stained as to be practically invisible. 
Figs. 56, 57. Antherozoids still within their enclosing vesicles, killed after leaving the 
antheridia. The body shown in Fig. 57, with deeply stained margin and somewhat irregular 
outline, is probably the limosphere. 
Fig. 58. An antherozoid beginning to escape from its vesicle. 
Tig* 59* An antherozoid which has become free. Cytoplasmic remnants are still attached to 
the posterior portion of its body. 
