ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
627* 
strgium ) ; Hypneae ( Heterophyllon , Drepanium, Ctenidium , Ptilium, 
Limnobium , Chrysohypnum , Hypnum, Hyocomium , Hylocomium). (5) 
Bendroideacese, with three groups : — Cryptocarpae (only exotic species) ; 
Orthocarpae (Climac urn) ; Camptocarpae ( Thamnium ). The exotic 
Hypopterygiaceae form an additional order. 
Algae. 
Iodine in Algse.* — According to M. A. Gautier, the average propor- 
tion of iodine in seaweeds is about 12 mgrm. per 100 grm. in the fresh, 
60 mgrm. per 100 grm. in the dried plant. He finds the same element to 
be invariably present in fresh-water algae belonging to all the different 
classes, though in much smaller quantities, the proportion varying 
between 0*25 and 0*40 mgrm. per 100 grm. in the dried plant. It was 
found in Ulothrix dissecta , Cladophora fracta, Nostoc fragile , Proto- 
coccus pluvialis, Batrachospermum sp., and the algal element of Peltigera\ 
also in Beggiatoa. In the other species of Fungi and Schizomycetes 
examined, iodine was either entirely wanting (diphtheria bacillus), or 
present only in exceedingly minute quantities (tetanus bacillus, Agaricus 
campestris, Boletus edulis, Cantharellus cibarius). 
Gigartina.t — Mary E. Olson has studied the structure of this genus 
of Florideae from an undescribed species growing near Washington, 
U.S.A. The tissue of the holdfast (hapter) is characterised by cells 
liaviug a quadrilateral outline, arranged in approximately regular rows 
extending vertically through it. In the pith there is an intimate proto- 
plasmic connection between the contents of neighbouring cells. The 
cystocarp is compound, and the spores are aggregated into distinct 
groups. The cystocarps are constantly infested with the fronds of 
another small epiphytic alga. Nematheces were observed in one 
instance. 
Constan tinea. J — Mr. E. M. Freeman describes the structure of this 
genus of Florideae, of which he considers that all the alleged species 
should be reduced to one, C. rosa-marina. The celly of the intermediate 
area of the frond are packed with florideae-starch grains, and these cells 
communicate with one another by protoplasmic connections, as also do 
those of the cortical area of the stipe. Tetraspores are known in only 
one sub-species, and are lodged in nematheces. Imbedded in the cortical 
tissue of the frond are numerous green spherical bodies which are endo- 
phytic algae, probably Chlorochytrium inclusion. 
Actinococcus and Phyllophora.§ — Dr. O. Y. Darbisliire now accepts 
Schmitz’s view (in opposition to his own previous conclusion) that the 
so-called nematheces of Phyllophora Brodsei are in reality those of a 
parasitic alga, Actinococcus subcutaneus (Lyngb.) K. Rosenv. (A. roseus 
Ktz.). The following is given as the diagnosis of the genus Actino- 
coccus Thallus parasitic on other Florideae, the vegetative portion 
consisting of filaments branching in the interior of the host-plant (intra- 
* Comptes Rendus, cxxix. (1899) pp. 189-94. 
t Minnesota But. Studies, 1899, pp. 154-68 (2 pis.). 
X Tom. cit.. pp. 175-90 (2 pis.). 
§ Ann. of Bot., xiii. (1899) pp. 253-67 (1 pi. and 7 figs.). Cf. this Journal, 1894, 
p. 484. 
