582 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(Edogonium.* — F. E. Fritsch describes the germination of the zoo- 

 spores in 0. capillure Kiitz., and his observations do not altogether 

 agree with those of Kiitzing or of Poulsen. He finds that the first can 

 is not thrown off in O.eajjillare, nor in other undetermined species which 

 he has examined. 



Ida A. Keller t describes and figures a peculiar condition of a species 

 of CEdogonium, which was kept in a jar of water at a window from autumn 

 to early summer. The alga, which at first was green and luxuriant, was 

 found in May to have lost its chlorophyll, and many of the cells were 

 closely packed with starch ; the plants were, however, perfectly healthy 

 and had remained rooted to pieces of rock. Since no oogonia had been 

 formed duriDg the previous autumn, it is probable that the food-material 

 stored up for their formation had remained in the cells in the form of 

 starch. 



Characeae from Co. Monaghan.J — G. E. Bullock- Webster describes 

 his researches among the numerous pools and lakes of Co. Monaghan in 

 August 1901. His most interesting finds were the following (both new 

 to Ireland) : Nitella mucronata Kuetz. in plenty near Carrickmacross, 

 and N. flexilis var. nidifica Wallm. in Co. Cavan. He points out the 

 similarity of the black 'peat and shell-marl in Ireland with those found 

 in the fens of Cambridgeshire, and quotes a theory that this shell-marl 

 may be due largely to the decay of Characeae. 



Observations on Pterygophora californica.§ — Conway McMillan 

 describes this alga as being larger than has hitherto been supposed and 

 attaining a length of 10 ft. with trunks of 3 in. in diameter. He places 

 it, as regards systematic position, between Laminariese and Alariideae. 

 The holdfasts show distinct rings of growth due to differences in the 

 cell-contents, produced by the varying amount of polysaccharids, allied 

 to mucine. Eings of growth are also visible in the stipe, produced in 

 some cases by the same condition as that described for the holdfast, ami 

 in others by the larger or smaller lamina of the cells. Polysaccharid 

 idioblasts are abundant in the cortex of the lamina, and these often 

 become exhausted during the formation of sori. The son, which are 

 here described for the first time, are formed in December in irregular 

 patches towards the base of the pinnae ; the paraphyses resemble those of 

 Lessonia in the disposition of the cuticular caps. 



Recent Publications on Diatoms.|| — P. T. Cleve makes critical 

 remarks upon Karsten's Die Diatomen der Kieler Bucht (1899) ami 

 corrects some of the specific determinations, while C. Mereschkowsky 

 criticises the information about the cell-contents. Cleve also corrects 

 several of the species names in Mereschkowsky's Etudes sur VEndo- 

 chrome des Diatomees (1901) ; Heid en-Rostock's Ih'rt*o?zieen des Converter 

 Sees bei Doberan (1900) ; Schiitt : s Certrifugale und simultane Membran- 

 verdickungen (1900); Schroder's Das Phytoplankton des Golfes von 

 Neapel. 



* Aim. Bot., xvi. (1902) pp. 412-7 (fig. in text). _ 



+ Proc. Acad. Nat. Sci. Philadelphia, liii. (1901) pp. 598-601 (figs, in text). 



% Irish Naturalist, xi. (1902) pp. 141-6. 



§ Minnesota Bot. Stud., ser. ii. xli. (1902) pp. 723-41 (G pis.). 



|| Ann. Mag. Nat. Hist., x. (1902) pp. 27-3S. 



