56 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
and Selciginella ruspidata var. elongata, Herr W. Arnold maintains that 
the development of the female prothallium presents no essential difference 
in these two genera. The single nucleus of the spore divides gradually 
into daughter-nuclei, which are imbedded in the parietal part of the 
protoplasm, and determine the formation of cells in the prothallium. 
The mature prothallia closely resemble one another ; they are colourless, 
and bear only unicellular rhizoids ; the spores germinate while still in 
the sporange, falling out, in Selaginella, at the time of impregnation; 
while in Isoetes the young plants are produced within the sporange. The 
process is compared by the author to the development of the endosperm 
in Phanerogams. 
Sporanges on Prothallia.* — Mr. W. H. Lang describes the production 
of sporanges on prothallia of two ferns, Lastrea dilatata var. cristata 
gracilis, and Scolopendriwm vulgare var. ramulosissimum. In the case of 
the former species the midrib of some of the prothallia was elongated 
into a peculiar cylindrical process containing tracheids. On this pro- 
cess are produced sexual organs of both kinds ; also sporanges, either on 
the process or immediately behind it, and either isolated or collected into 
groups resembling sori ; also single sporanges on the edge of the pro- 
thallium. Beneath the sporanges a few tracheids were always found. In 
the hart’s-tonguc the prothallium was prolonged into a similar cylindrical 
process, which bore a large number of sporanges as well as sexual 
organs. The author adduces reasons for regarding the production of 
sporanges on the prothallium as a special case of apogamy. 
Bivision of the Prothallium of a Fern.f — Mr. E. J. Lowe records 
some interesting results from the repeated division of the prothallium of 
Scolopendrium vulgare var. crispum. Some of the fern-plants which 
sprang from the divided prothallia had a remarkably Marcliantia- like 
appearance. These fronds appear to have characters intermediate be- 
tween the sporophoric and the oophoric. Apospory was also observed, 
as also the formation of antherids and archegones on an entirely new 
growth of repeatedly divided prothallia. 
Muscineae. 
Mucilaginous Paraphyses in a Moss.J — In some of the paraphyses 
of Diphyscium foliosum , Herr W. Lorch finds bell-shaped membranes 
attached to the septa. In their youngest stages, an accumulation of 
mucilage takes place between the cuticle and this membrane, which dis- 
tends and finally splits the cuticle, producing the bell-shaped structures. 
Algae. 
Sarcomenia.§ — Mdmo. A. Weber van Bosse describes minutely the 
structure of Sarcomenia miniata (Florideae) from South Africa. The 
cells of the central tube are connected by a very strong strand of proto- 
plasm. Secondary pores and smaller strands of protoplasm also con- 
nect the pericentral tubes with one another and with the central tube. 
* Proc. Roy. Soc., lx. (1896) pp. 250-60. 
t Journ. Linn. Soc. (Bot.\ xxxii. (1896) pp. 529-39 (2 figs.), 
f Jahrb. Naturw. Yer. Elberfeld, viii. (1896) p. 86 (1 fig.). See Hedwigia, xxxv. 
(1896) Rep., p. 121. § Journ. of Bot., xxxiv. (1896) pp. 281-5 (1 pi.). 
