iio Davie. — Development of Peranema cyatheoides , D. Don. 
DESCRIPTION OF PLATE III. 
Illustrating Mr. Davie’s paper on Peranema cyatheoides , D. Don. 
Fig. i has been drawn with the aid of an Abbe camera lucida. 
Figs. 2, 3, 4, 5, 6, 7, 8 have been drawn with the aid of a Leitz drawing apparatus. 
Fig. i. Vertical section through a very young sorus of Peranema cyatheoides , D. Don, showing 
one large indusial flap almost completely covering the receptacle. No sporangia have been developed 
on the receptacle. At the right side there are one or two cells with thickened cell-walls, representing 
the laggard portion of the indusium. x 225. 
Fig. 2. Vertical section through a slightly older sorus. The receptacle has become extended 
through the gap between the portions of the indusium. The laggard portion of the indusium is now 
distinct, and the whole indusium shows a cup-shape. One sporangium is initiated near the lower 
margin of the receptacle, x 150. 
Fig. 3. Vertical section through a young sorus, showing the modified cup-shape of the indusium. 
One portion of the indusium completely overlaps the receptacle. A sporangium is just initiated 
near the junction of the receptacle and the large indusial flap, x 150. 
Fig. 4. Vertical section through an older sorus, showing the extension of the large indusial flap 
over the receptacle, which is now widely dome-shaped. Two sporangia of approximately equal age 
occupy the summit of the receptacle; younger sporangia occur nearer its edges, x 150. 
Fig. 5. Vertical section through an older sorus, showing the extension of the receptacle and the 
cells continuous with those of the indusium, forming the start of the ‘ stalk ’ of the sorus. The cells 
at the base of the receptacle, in the developing stalk, are considerably elongated and narrow, but no 
tracheides are at this stage present in the sorus. One sporangium is seen at the summit of the 
receptacle, x 150. 
Fig. 6. Transverse section across a mature sorus just above the junction of the stalk and the 
sporangium-bearing portion. The lips of the large indusial flap are shown on the upper side of the 
figure. On the lower side, in the right-hand corner is one of the pocket-extensions of the indusium, 
covering several sporangia. In the left-hand corner is the upper part of a similar pocket, which 
extends further down the stalk than the right-hand pocket, x 35. 
Fig. 7. Unicellular glandular hair from the cushion of the prothallus. It is situated upon 
a single superficial cell, the wall of which is raised slightly above the general level of the surface 
of the prothallus. x 330. 
Fig. 8. Vertical section through an antheridium, showing a divided lid-cell, and containing 
several coiled spermatozoids. x 330. 
