Physiologie. — Algae. 487 



hyde (CH 3 ) 3 j N(OH) . CH2CHO, though the muscarine pre- 

 pared by Oxydation of choline is (CHa 13 : N (OH) . CH2 CH (OH)2. 

 Neurine is (CHs)s \ N(OH)CH : CH 2 . 'PI immer finds betaine 

 in considerable quantity (3,75 per 1000 in the sample examined) 

 in raw beet sugar. 



The order of toxicity oi the above-mentioned substances 

 is as follows: 



1. Neurine and Muscarine. 



2. Choline and Beta'ine. 



The first two being considerably more toxic than the 

 others. The effect on isolated, nerve is a diminution of electro- 

 mobility. On the excised heart the effect of all four sub- 

 stances is arrest in diastole. 



The effect can in each case be counteracted by atropine. 



E. Drabble (London). 



Wosnessennsky, Mlle, E., und Mlle E. Elisseeff, Ueber den 

 Athmungscoefficient verschiedener Heferassen 

 in Rollculturen auf diversen Stickstoff n ähr- 

 substraten. [Aus dem bot. Laborat. d. St. Petersburger 

 Frauenhochschule.] (Travaux de la Soc. Imp. des Naturalistes 

 de St. Petersbourg. Vol. XXIV. Livr. 1. No. 3. Mars 

 1903. p. 108—118. Russisch mit deutschem Resume. p. 132 

 — 133.) 



Es wurden cultivirt: Saccharomyces Cerevisiae I Hannsen. 5. Lud- 

 wlgii und Schizosaccharomyces Pombe. Der Stickstoff wurde als Pepton 

 (1°/..), PCMNH«),H (0,47"/..) und NOsK (0,72°/..) in die Nährsubstrate ein- 

 geführt. Die Resultate der Versuche sind folgende: 1. Die Athmungs- 

 coefiiciente hängen von der Heferasse und dem Nährsubstrate ab. Bei den 

 Heferollculturen wurden meistentheils grosse Athmungscoefficiente gefun- 

 den, woraus man schliessen kann, dass in diesen Fällen, ungeachtet der vollen 

 Aeration, alkoholische Gährung stattfindet. Die Coefficiente wuchsen 

 allmählich mit der Entwickelung der Hefe, was die Buchner'sche 

 Zymasetheorie, nach welcher sehr junge Hefe keine Zymase bildet, be- 

 stätigt. 3. Schizosaccharomyces Pombe liefert auf phosphorsaurem Am- 

 moniak sehr kleine Coefficiente, was auf die Abwesenheit in diesem Falle 

 der alkoholischen Gährung hinweist. W. Tranzschel. 



W'ESENBERG-LUND, C, Sur les Aegagropila Saut er i du lac de 



Sorö. (Acad. roy. des Sc. de Danemark. Bull. 1903. 



p. 167 — 204. Avec une carte.) 



Aegagropila Sauteri is extremely common in the lake of Sorö 

 (Denmark), every spring the large spherical bodies are floating on the 

 surface of the water. The author has tried to explain the biological 

 features of this alga. The bottom of the lake at a depth of ab. 4 M. is 

 covered with a dense layer of small (10 — 20 mm. long) individuals of the 

 alga, which also forms coherent couches over stones and other bodies; 

 in more shallow water (1,00—1,50 M.) this layer does not occur, but here 

 we find spherical bodies lying loosely on the bottom; these bodies 

 rise in spring to the surface. They float isolated or several individuals 

 are entangled; the rising is caused by the assimilation, the bubbles of 

 air not being able to escape from the central parts of the densely aggre- 

 gated filaments of the sphere. When the spheres break into pieces, the 

 fragments often become matted and form large felt-masses. For further 

 details the paper itself must be consulted. C. H. Ostenfeld. 



