Physiologie. — Palaeontologie. — Algae. 7 



animal pepsin, while the Endopeptases include those respresen- 

 tatives, extracted from plant-tissues very readely by NaCl Solution, 

 which work best at natural acidity and are inhibited by more than 

 a trace of mineral acid. J. J. Blackman. 



White, J., The ferments and latent life of resting seeds. 

 (Proc. royal Soc. LXXXI. B. 550. p. 417—442. 1909.) 



The Intention of this work is to ascertain whether there is any 

 correlation between the retention of vitality by seeds and the pre- 

 sence of enzymes in them. The enzymes were extracted from fresh 

 grains of various cereals and from grain which had lost its power 

 of germination by being kept in störe for a number of years. Sam- 

 ples of wheat from one region of Australia lost their vitality com- 

 pletely in 10 years, from another region in 14 years but in none of 

 these nor in grain stored 21 years did there seem to be any dimi- 

 nution in the amount of diastase, pepsin or erepsin. Loss of active 

 enzymes is clearly not the cause of death and experiments also give 

 no Support to the preposterous old assertion that treating seeds with 

 Solutions of enzymes facilitates their germination. 



A few hours heating at 100° C of dried seeds was found to 

 destroy their vitality but to leave the enz^^mes unimpaired. Expo- 

 sure to liquid air also had no effect upon the enzymes though 

 germination was in most cases retarded. 



The last section of the paper shows that air-dry seeds in some 

 cases give out traces of C0.2 (wheat gives off a surprising amount), 

 and take in O2. but that this is stopped by moderate drying at 45° C. 



Traces of Oxygen may however be taken in ver}^ generally by 

 dead seeds and bits of wood as well as living seeds. 



J. J. Blackman. 



Salfeld, H., Die Flora des Palaeozoikums, speziell die des 

 Carbon, im Lichte der neuesten Forschung. (2. Jahrber. 

 Niedersächs. geol. Verein, p. 59 — 64. 1909.) 



Behandelt die Pteridospermenfrage. „Nach unserer heutigen 

 Kenntnis ist es wahrscheinlich, dass vom Carbon an das g3'mno- 

 sperme Element vorherrschend war; vielleicht mag dies schon im 

 Devon der Fall gewesen sein." Gothan. 



Stark, P., Pflanzenreste im Buntsandstein des südwestli- 

 chen Kraichgau. (Ber. Versamml. oberrhein. geol. Verein. XLII. 

 p. 129-141. 9 Textfig. 1909.) 



Verf. giebt eine Anzahl von Buntsandsteinpflanzenfundstellen 

 an aus der Gegend von Durlach {Anomopteris Mougeoti, Eqiiiseti- 

 ten-, Voltsia, } Pleuromeia- u. a. Reste). Der Erhaltungszustand ist 

 ebenfalls besprochen. Gothan. 



Ganong, W. F., On balls of vegetable matter from sandy 

 shores (second article). (Rhodora, XI. p. 149—152. 1909-) 



The author describes the aegagrophila formed of algae, mainly 

 Dictyosiphon , Desrnarestia , Ectocarpus, CJiordaria and Chorda from 

 Nova Scotia and certain hair balls rolled ashore along Little 

 Traverse Bay, Lake Michigan. The most important European 

 papers are cited. J. W. Harsberger. 



