82 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Floridese occurs an amyloid substance which is stained by iodine to a 
violet, more or less brownish, or more or less reddish, indicating varia- 
tions in its constitution. Sometimes it is restricted, sometimes diffused 
through all the cell-membranes, except the cuticle. Its general presence 
in the Gelidium group suggests that it plays a part in the j edification 
of this group ; yet it occurs in Halopithys and Laurencia which yield 
no gelose ; and also at the rhizoidiferous base of Porphyra , though its 
cell-walls differ chemically from those of other red algae in containing 
no cellulose. By further micro-chemical research it is found that there 
is an amyloid of the nature of starch, and a second one of the nature of 
the dextrines. A. Gf. 
Corallinaceae of the Tripoli Coast. — R. Raineri ( Nuova Notarisia, 
1921, 32, 133-49). The material of this work was collected by Prof. 
Parona in 1912-13 during the Italian Scientific Expedition to the 
Libyan coasts. The Corallinaceae form a living embankment or reef in 
course of formation. The species recorded belong to Lithothamnium , 
Lithophyllum and Melobesia, and are discussed individually, the structure 
being described and figured. Two species of Gorallina and Peyssonnelia 
rubra Grev. are also recorded from the protected rocky coast. E. S. G. 
Fossil Corallinaceae of Libya. — R. Raineri (AtM Soc. Ital. Sci. 
Nat., 1920, 59, 137-48, 7 figs. ; see also Nuova Notarisia , 1921, 32, 
167). A report on material collected by Prof. Parona. Four new 
species are described, including Arthrocardia cretacica and Amphiroa 
Mattiroliana. These genera have not previously been recorded from 
Oretacean strata. Archseolithothamnium Paronai and Lithothamnium 
lubicum are also new to science. Other known species are discussed. 
E. S. G. 
Dwarf Generation in Pogotrichum and the Reproduction of 
Laminaria. — P. Kuckuck ( Ber . Deutsch. Bot. Gesell., 1917, 35, 
557-58 ; see also Bot. Gentralbl ., 1919, 140, 151). The first part of 
this paper is devoted to a consideration of “ prospory ” in Pogotrichum 
filiforme Rke., a phenomenon already described by the author, but not 
taken up in current literature. On the basal disc, from which later the 
upright thallus is developed, plurilocular sporangia are formed, and on 
the upright thallus are unilocular ones. The two phases occur in 
seasonal succession, the dorsiventral basal-disc thallus predominating in 
spring, and later on the upright radial thallus. This should be of 
interest in studying the development of alternation of generations. 
Germination of the spores of the upright thallus produced very reduced 
plantlets, which consisted sometimes only of one vegetative cell and a 
plurilocular sporangium. The author considers it not impossible 
that these forms may also occur in nature. In the second part of the 
paper the author discusses the work of Sauvageau on the dwarf sexual 
generation of Saccorhiza bulbosa, and describes a similar phenomenon in 
Laminaria saccharina. Minute prothallia are developed, bearing 
oogonia and antheridia. Spermatozoids and the process of fertilization 
have not yet however been observed. The female thalli can produce 
more than one oogonium ; the male thalli bear antheridia in close 
