-_ 
52 
soon ruptured and the antherozoid swims rapidly away, dragging 
after it the remains of the contents of the mother-cell as a very 
delicate vesicle (Fig. 7, v.) 
The body of the antherozoid is coiled, the coils toward the 
posterior end being larger. It is generally somewhat flattened 
at the anterior end, where there are numerous cilia, and more or 
less pointed at the other, which may be drawn out into a long, 
delicate filament. 
After the escape of the antherozoids the inner walls of the 
antheridium (Fig. 6) soon assume a dark brown color. 
In the preparation of specimens for study, very little use was 
made of reagents, most of the work being done with living speci- 
mens mounted simply in water. 
EXPLANATION OF FIGURES. 
Fig 1. Small male prothallium of Asplenium filix-femina ; 
xX 150. Ax, antheridia; 7, root hair. 
Figs. 2-5. Successive stages in the development of the an- 
theridium of thesame; X ae All except Fig. 4 in optical lon- 
gitudinal section. 
Fig. 6. An empty antheridium of the same; x 550. 
Fig. 7. Antherozoids of the same; a, before, 4, after escaping 
from the mother-cells, x 625; v, vescicle:—remains of the cen- 
tral contents of the mother-cell. 
Fig. 8. Young antheridium of Onxoclea sensibilis. Optical 
section from the side; X 500. * 
Fig. 9. An older one of the same species from above; 
xX 500. 
New American Grasses. 
By GEORGE VASEY. 
ARISTIDA REVERCHONI, Vasey.—Culms slender, 1 to 2 
feet high, unbranched, smooth; radical leaves 3 to 6 inches long, 
involute filiform, straight or curved; culm leaves about 3, rigid, 
_ erect, filiform and involute, 3 to 6 inches long; ligulea ciliate 
line ; sheaths smooth, close, shorter than the internodes; panicle 
erect, spike-like, slender, 4 to 6 inches long; the branches 
appressed and sessile, single and alternate, the lower ones I to 1% 
inches long, all closely flowered, and longer than the internodes; 
