474 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Spirogyra.* — U. Kasanowsky and S. Smirnoff publish the first 

 section of a Flora of the waters in the neighbourhood of Kievv. It 

 deals with the genus Spiroyyra, for which one new species and some new 

 varieties are described. Twenty-five species are recorded. A table is 

 given showing the distribution of forty-one species of Spirogyra round 

 Kiew, Moscow, Charkow, etc. 



Division of Mitochondria in Vaucheria.f — F. Moreau gives a 

 resume of what is known of chromatic bodies. He has studied them 

 in Vaucheria in the light of Rudolph's recent work, and agrees with 

 him that they are mitochondria. But he has gone further, and shows 

 that the supposition that the mitochondria divide is an actual fact. 

 He claims to have observed a clear division occurring. And this lends 

 support to the theory that the mitochondria cannot form de novo in 

 the protoplasm, but that each of the mitochondria springs from a pre- 

 existing one. 



Dichotomosiphon and Mischococcus.J — J. Virieux publishes notes 

 on two rare algas. 1. Dichotomosiphon tuberosus is a rare alga gathered 

 years ago by Braun in the lakes of Granson and Zuricn, and recently 

 found in North America, and by Virieux near Besancon. Ernst lifted 

 it out of Vaucheria and made it the. type of a new genus, Dichoto- 

 mosiphon, with fruit unknown. Virieux has now found it in the fertile 

 state. Dichotomosiphon is characterized by deep-green tuberous produc- 

 tions enclosing chloroleucites without pyreuoids and starch. These organs 

 are not galls of Notommates nor aplanospores ; rather they recall 

 akinetes, and are altogether comparable with the tubercles of the higher 

 plants. In germination they emit seven or eight tubes. Zoospores are 

 unknown ; but the sexual organs are developed in clusters of three to 

 six oogonia, some of which can present a char commencement of 

 tuberization. Dichotomosiphon is a very valid genus, and cannot be 

 included under Vaucheria, but rather shows relations with the Codiaceaj 

 in its vegetative structure and reserve starch. 2. Mischococcus oon- 

 fervicola has a stage in its development which is characterized by the 

 formation of loculi (j>seudo-Dinobryon phase). This follows the forma- 

 tion of the characteristic ramification by a special process. The 

 abundant mucilage of this alga is of a pectic nature. The genus 

 belongs to the Botryococcacese, forming a tribe with Ghlorosaccus and 

 Racovitziella. 



Porphyridium cruentumj — H. Kufferath writes on the physiology 

 and morphology of Porphyridium cruentum Nag. He has succeeded 

 in obtaining pure cultures of it by methods which he describes. He 

 notes the absence of a pyrenoid, and explains that its supposed presence 



* Kiewsk. Ooscestvo Guit. prirod. dnepr. biolog. stan. No. 4 (Kiew, 1914) pp. 1-36 

 (1 pi. and 3 figs). See also Bot. Centralbl., cxxv. (1914) p. 622. 



t Bull. Soc. Bot. Prance, lxi. (1914) pp. 139-42. 



X Bull. Soc. Hist. Nat. Doubs (1911) 9 pp. (1 pi.). See also Bull. Soc. Bot. 

 France, lix. (1913) pp. 657-8. 



§ Bull. Soc. Roy. Bot Belg., lii. (1913) pp. 286-90. 



