Affinities of Peranema and Diacalpe. 255 
sporangium must be weighed against the long stalk of the sporangium and 
the mixed condition of the sorus in estimating the systematic position of 
Peranema. For the present it may be noticed that they all indicate that 
Peranema occupies an interesting position intermediate between Gradatae 
and Mixtae, and combines in its mechanism for spore production and 
dispersal the main characteristics of both groups. 
The spores are very characteristic. They are of somewhat large size, 
and have on their surfaces very peculiar markings (Fig. 21). Each spore 
is surrounded by a membrane which encloses it rather loosely. At certain 
points, perhaps four or six or more, on its surface, the membrane is attached 
to the spore itself. These points take the form of little circular discs, each 
with a minute papilla in its centre, a portion of the membrane detached 
from the spore wall and filled with air. As a result of the presence of these 
circular pits and their included papillae, the surface of the membrane appears 
to be crossed by a series of folds of irregular shape. These are of course 
the portions of the membrane surrounding the circular pits, portions which 
are quite free from the spore. Such markings are found with some slight 
variation among many genera of Polypodiaceae, particularly in the genus 
Aspidium . They have lately been described by Hannig (Tl). He finds 
that in the Cyatheaceae (loc. cit., p. 342), and in the genus Polypodium 
(p. 344), there is no loose membrane ( £ perispore ’) around the spores. From 
the characteristic appearance of the perispore in the genus Aspidium he has 
been led to distinguish spores surrounded by a similar perispore as ‘aspidioid 
He remarks (p. 340) that the genera Peranema , Diacalpe , and Woodsia 
possess aspidioid spores. 
Unfortunately the first set of germinated spores in the Glasgow Botanic 
Gardens damped off before the antheridia had developed upon the prothalli, 
and the second set have not yet produced antheridia. The first stages of 
development are quite normal. The later stages have not been available, 
and no conclusions can therefore be made from the characters of the 
gametophyte generation. 
DIA CALPE A SPIDIOIDES, Bl., was first described by C. L. Blume 
in his £ Enumeratio Plantarum Javae et Insularum adjacentium published in 
1828. From the genus Woodsia , R. Br. ? to which he says it bears close affinity, 
Blume separates it because the indusium is not ‘ dish-shaped and ciliated 
He places it in the third section of Kaulfuss’s family Polypodiaceae, 
a section characterized by the sporangia being borne on receptacles, 
and by the indusium springing from below the sorus or being altogether 
absent. In the same section are included also Cyathea , Alsophila , and 
Hemitelia. Diacalpe grows, he remarks, £ in sylvis Javae altissimis 
It is included in the Appendix to Presl’s £ Tentamen Pteridographiae * 
( i 836), with the query : £ An Cyatheacea, an Cathetogyrata stirps ? ’ 
