694 SUMMARY OF CURRENT RESEARCHES RELATING TO 



plant 90 m. in length he regards as incorrect, and quotes MacMillan's 

 record of NO ft. As to the question whether or not it is an annual, he 

 says that, except for a few stragglers, all the plants noticed by him the 

 previous summer had gone in March of this year. Young plants of 

 1' 25-2* 5 m. long, with bulbs 12-88 mm. in diameter, and fronds 

 30-90 cm. in length, were to be seen growing on the bottom, 3-9 m. 

 under the water. They do not reach the surface the first year, but 

 remain out of reach of waves, pushing rapidly up in the second season, 

 only to die when winter overtakes them. The growth is very rapid, and 

 the author calculates that it is as much as 25 cm. a day at one time. 

 The stalk is firmly anchored to the rocks by holdfasts covering an area 

 as much as 30 cm. in diameter. 



Constantinea.* — W. A. Setchell has made a study of this genus, and 

 comes to the following conclusions : — 1. The genus Constantinea is to 

 be restricted to the three species, C. rosa-marina, C. simplex, and 

 G. subulifera. 2. Thus constituted, it is a genus of the Dumontiacese, 

 as defined by Schniitz and Hauptfleisch ; it is characterised by the 

 possession of cylindrical, annulate, and more or less dichotomously 

 branched stipes, bearing orbicular laminae, at first peltate or nearly so, 

 later perfoliate, entire, or more or less radiately split, and by the posses- 

 sion of nemathecia containing zonate tetraspores accompanied by 

 unicellular paraphyses. 3. C. rosa-marina is identical with G. sitchensis 

 P. and R. 4. The author founds his new species, C. subulifera, on the 

 plant collected by Harvey in N.W. America, and named by him 

 C. sitchensis. 5. The genus is confined to the Northern Pacific and 

 Bearing Sea. The separation of the species is clearly shown by means 

 of an analytical key. The synonymy of the three species is detailed, with 

 a list of exsiccatae ; and G. subulifera is described. 



Cladophora crispata and the Section JSgagropila.f — F. Brand 

 publishes the result of his further studies on Cladophora, and deals with 

 the differences between the attached and the free-swimming forms. He 

 shows that G. fracta is no independent species, but merely the free- 

 swimming form of C. crispata. He gives an emended diagnosis of 

 C. crispata, to which he reckons also G. vitrea Kutz., C. regularis Kutz., 

 G. virescens Kutz., C. brachyclados Kutz., C.putealis Kutz., C. brachy- 

 stelecha Rabenh., and C. glomerata var. stagnalis Brand ex parte. His 

 former treatment of the section iEgagropila is supplemented by further 

 remarks and a description of a new fresh-water species of the group 

 which was found by Professor Lagerheim in a lake in the neighbourhood 

 of Stockholm. Brand names the plant G. Lagerheimii ; it is distinguished 

 from all other species of the group by the occurrence on some of the 

 filaments of pinnate branching. An amplified diagnosis is also given of 

 G. profunda Brand. The difficulty of determination of species is realised 

 by the author, and comparative tables are given of the habit and struc- 

 ture of C. glomerata, C. crispata, and C. fracta, as representing Euclado- 

 phora, and the group of Euasgagropila. A valuable summary is given 

 of the characters of fixed, as opposed to free-swimming, species. Plants 



* Nuov. Notar., xvii. (1906) pp. 162-73. 

 t Hedwigia, xlv. (1906) pp. 241-59. 



