144 SUMMARY OF CUKRENT RESEARCHES RELATING TO 



end of the jDaper the results are summarized. The algal flora of 

 Barton's Pond is dominated by a successive association (formation ?) of 

 Microspora, Eunotia arms, Conferva, Zygnemacese, Oedogonium, Proto- 

 coccales, Euglena, Anabsena, species of Trachelomonas and epiphytic 

 Diatoms. The flora is very rich and shows a very pronounced 

 periodicity, related somewhat to that of the phanerogamic flora. Four 

 main phases are distinguishable in the annual cycle : 1. Winter phase, 

 with an abundance of Microspora and Diatoms. 2. Spring phase, with 

 dominant Z/jgnemaceae and Oedogonium, and numerous Frotococcales as 

 subsidiary forms. 3. Summer phase, with dominant Eugle?ia and 

 Analsena, Imffigiata and Desmids being important subsidiary forms. 

 4. Autumn phase, chiefly characterized by renewed development of 

 many of the filamentous forms and by the presence of species of 

 Trachelomonas and Oscillariese. A profound relation between the 

 frequency of the algal flora and the meteorological conditions has been 

 established. The relation between sunshine and the sexual reproductive 

 process is very plain, confirming Klebs's conclusions. 



DicranochaBte reniformis.*— W. J. Hodgetts gives a detailed account 

 of the minute anatomy, reproduction and life-history of Dkranochaete 

 reniformis, a small green alga which was originally discovered in Silesia, 

 was described by Hieronymus in 1887 and ]'890, and has recently 

 been found near Birmingham — the first record for this country. Owing 

 to its long branched setaB Dkranochxte holds a somewhat isolated 

 systematic position. The only other species that has been recorded is 

 D. britannica G. S. West, which was gathered in mountain pools of 

 North Wales in 1912. 



New Penetrating Alga.f — Elizabeth Acton gives a description of 

 Gomontia JEgagropilse, a new green alga found growing in the walls of 

 dead cells of Cladophora {^gagropila) holsatlca, collected in Loch 

 Kildona, Hebrides, and cultivated for some years in a pie-dish. The 

 Gomontia had also penetrated and spread beneath the glazed surface of 

 this pie-dish at numerous spots. The author describes and figures the 

 structure and raniification of the alga, and its means of multiplication. 

 She also discusses its systematic position, and reviews the three genera 

 of boring algae — Gomontia, TeUamia and Foreliella. Tellamia she 

 transfers to Endoderma ; and Foreliella she unites with Gomontia. 



Tetracyclus.l — F, Hustedt publishes some critical studies on the 

 structure and systematic position of the genus Tetracyclus. The points 

 of systematic value are the form of the frustule, the girdle and the 

 septa. The species having the greatest power of variation is T. ellipticus 

 Grun. The various differences are indicated, with the resultino- forms. 

 Diagnoses are given of eleven species. Two others are uncertain, and 



* New Phytologist, xv. (1916) pp. 108-116 (1 fig.), 

 t New Phytologist, xv. (1916) pp. 97-102 (1 pi. and figs.), 



X Abh. Natur. Ver. Bremen, xxiii. (1914) pp. 90-107 (1 pi. and fig. in text). See 

 also Bot. Centralbl., cxxxii. (1916) p. 431. 



