Bower \ — Studies in the Phytogeny of the Filicales. 321 
Fig. C. Pinnule of Gleichenia linearis , showing venation and mature sori. Some of the sporangia 
are shown to have dehisced. Enlarged. 
Fig. D. A single sorus of Gleichenia linearis on a larger scale, showing the disposition of the 
sporangia, several of which have opened by a median slit. Enlarged. 
Fig. E. Pinnule of Gleichenia pectinata , showing the venation and mature sori. Some of 
the sporangia are shown to have dehisced. Enlarged. 
PLATE XXXI. 
Fig. F. A single sorus of Gleichenia pectinata , showing the sporangia so closely packed as to 
be flattened against one another. One has already dehisced. Note the inverted position of one 
of the outer sporangia on the right-hand side. Enlarged. 
Fig. G. Upright stock of Lophosoria , after removal of the hairy covering. The erect appendages 
are all foliar, of which those inserted lower down are abortive, while those higher up are developed. 
From the base of several of them, but not all, arise the horizontal, solenostelic runners. Note 
the emergences on the bases of the fully developed leaves. From drawing by Mr. Thompson. Half 
natural size. 
Fig. H. Pinnule of Lophosoria pruinata , showing venation and sori. Enlarged. 
Fig. I. A single sorus of Lophosoria , showing the small number of sporangia, with their 
regular orientation. Each sporangium has its annulus apparently complete, the stomium being 
lateral, and therefore out of sight. Enlarged. 
PLATE XXXII. 
Fig. K. Dissection of a large stock of Lophosoria pruinata, showing the vascular solenostele 
exposed, by the removal of all superficial tissues. It is clear that the foliar gaps do not overlap, 
and transverse sections anywhere in the internode will show the complete solenostele. From 
drawing by Mr. Thompson. Natural size. 
Fig. L. Dissection of a smaller shoot of Lophosoria pruinata, showing the vascular system 
exposed. The internodes are shorter than in Fig. K. Note the vascular supply to the runners 
arising horizontally from the bases of many of the leaf-traces. From a drawing by Mr. Thompson. 
Natural size. 
Fig. M. Double-headed specimen of Cyathea dealbata in the Glasgow Botanic Garden. It is 
probably a dichotomy. 
PLATE XXXIII. 
Fig. N. Plant of Hemitelia setosa in Edinburgh Botanic Garden, showing numerous 4 aphlebioid ’ 
pinnae. From a photograph prepared by the direction of Professor Balfour. 
Fig. O. Plant of Alsophila sp. in Glasgow Botanic Garden, showing basal pinnae, comparable 
with the 1 aphlebiae ’ of Hemitelia. 
PLATE XXXIV. 
Fig. i. Very young sorus of Gleichenia pectinata , seen in vertical section, before the sporangia 
have been initiated, x 400. 
Fig. 2. A similar sorus, rather older, x 400. 
Fig* 3* A similar section of an older sorus, on which the sporangia have already been initiated, 
x 400. 
Fig. 4. A similar section, showing some difference of age of the sporangia borne upon the same 
sorus. x 400. 
Fig. 5. A young sporangium of Gleichenia pectinata , showing a typical segmentation of the 
relatively massive stalk, x 400. 
Fig. 6. Section cut through a sporangium so as to traverse the sporogenous tissue in a plane 
transverse to the axis of the sporangium. The number of the spore-mother-cells is fifteen, x 400. 
Fig. 7. A similar section cut in the median plane of the sporangium, and traversing twenty 
spore-mother-cells, x 400. 
Fig. 8. A similar section, showing the spore-mother-cells separated and rounded off. x 400. 
Fig. 9. A large stem of Lophosoria cut transversely, and represented natural size. A leaf-trace, 
subdivided into three strands, has recently been given off, leaving an open foliar gap, while prepara- 
tion is being made for another opposite the mark x . 
