2j8 
Notes . 
was to be found. During the summer months the latter genus, 
however, attained an enormous development, the whole bottom 
of the pond being covered with a thin blue-green film from which 
dense, almost black masses of various shapes stood up vertically in 
the water. 
In the introductory remarks to the many algal lists that have been 
published I have as yet found little discussion on the periodicity 
of Algae. Hilse 1 in 1863 remarks of the Algae in the numerous 
small pools in the granite quarries of the Galgenberg near Strehlen : 
‘ Sehr bequem ist auch hier der Wechsel der einzelnen Arten zu 
beobachten. So findet man in den Jahreszeiten Fruhling, Sommer 
und Herbst in ein und derselben Wassersammlung sehr oft auch 
verschiedene Algen, ja manche dieser Species hat kaum eine Dauer 
von einigen Wochen (!)/ Bohlin 2 quite recently, in a very com- 
prehensive account of the algal flora of the Azores, remarks : ‘ II est 
sur qu’une certaine quantity de ces plantes sont, plus qu’on ne le 
pense en general, liees a certaines saisons.’ This remark applies 
to a tropical flora, but might equally well be applied to the develop- 
ment of an algal flora in our parts. The few remarks made by 
Schimper 3 on the periodicity of the water-plants all refer to the 
Phanerogams or to the Plankton. The writer is at present occupied 
with the collection of data concerning the periodical development 
of Algae in different parts of the South of England, and hopes 
at a future date to enter much more fully into this interesting 
subject. 
F. E. FRITSCH. 
Jodrell Laboratory, Kew, 
October 30, 1902. 
NOTE ON ABNORMAL PLURALITY OF SPORANGIA IN 
LYCOPODIUM RIGIDUM, Gmel.— Though few, if any, morpho- 
logical generalizations are without any exceptions, one which has 
hitherto stood, I believe, without any recorded instances to the 
contrary is that in the Lycopodinae (excl. Psilotacea) the sporophyll 
1 Hike, Netie Beitrage zur Algen- 11. Diatomeen-Kunde Schlesiens, insbesondere 
Strehlens, Abhandl. d. Schles. Ges. f. vaterl. Cultur, naturw.-medicin. Abtheilung, 
1863, Heft II, p. 57. 
2 Bohlin, Etude sur la flore algologique d’eau douce des Agores. Bihang till 
K. Svenska Vet.-Akad. Handlingar, Bd. 27, Afd. Ill, No. 4, 1901, p. 5. 
3 Schimper, Pfianzengeographie, p. 857. 
