190 P- Sydow: Pilze (ohne die Schizomyceten und Flechten). [3ß 



3. The spores are more sensitive to the OH-ions. They are repelled by 

 nearly Vioooo naol. or perhaps below that, of sodium hydroxide, while 

 the same concentration of hydrochloric acid is considered as the liminal 

 value for attraction. 



4. The H-ions contained in 1 l eo0 mol at any well-discociable acid are nearly 

 the maximal amount for attraction. At higher concentrations the act 

 repellently and injouriously. 



5. The attracting power of acids is parallel tho their dissociability, so that 

 a strong acid has a stronger action than a weak one. 



6. The repellent action of strong Solutions of acids may be dne in strong 

 acids to the supraoptimal amount of the H-ions and in weak acids, in 

 most cases, to undissociated acid-molecules. 



7. The repellent power of acid-molecules is weaker than the attracting 

 power of the H-ions, so that, when both components coexist in equal 

 amounts, the spores attracted by the H-ions are injured by the coexisting 

 acid-molecules. 



8. The action of acid-molecules differs more or less in different acids; 

 many of them act injouriously and cause shrinkage of the body of the 

 spores at necessary concentrations, while others, for instance, malic, 

 succinic, and tartaric acids, induce at first chemokinesis, that is, check 

 of movement. 



9. Many acidic salts (comprising such salts as give acidic reaction in Solu- 

 tion by hydrolysis) are less toxic or repellent than those of free acids. 



10. Both positive and negative Chemotaxis is typically phobotactic, or 

 to use Jennings' terminology, the reaction is a form of a „motor reflex." 



11. In determining the liminal value („Schwellenwert") of agents for chemo- 

 tactic Stimulus the usuel capillary method of Pfeffer appears to be un- 

 reliable. The value found by this method is inconsistent with other 

 plrysiological effects; for instance, it is larger than the toxic value, or 

 it is not is ohydric in all acids. 



12. From the biological point of view the H-ions act beneficially to the 

 development of Myxomycetes, they promote the germination of the spores 

 on the one hand and lead the swarm-spores to the place where much 

 food-materials are liberated on the other. 



13. The toxic effects are different in different acids; the toxicity is due 

 either in the H-ions (many in organic acids) undissociated molecules 

 (many less dissociable organic acids), or anions (picric acid). 



436. Kasano, S. A contribution in the cytology of Synchytrium 

 and its hosts. (Bull, of the College of Agriculture Tokyo Imp. Univ., VIII, 

 No. 2, 1909, p. 79—147, tab. VIII— XI.) 



Verf. untersuchte die cytologischen Vorgänge bei Synchytrium Puerariae 

 auf Pueraria Thunberglana und S. decipkus, 



437. Latham, Marion E. Nitrogen assimilation of Stcrigmatoeystis 

 nigra and the effect of chemical Stimulation. (Ball. Torr. Bot. Club, 

 XXXVI, 1909, p. 235—244.) 



Bestätigung der Bindung von freiem Stickstoff durch Sterigmatocystis nigra. 



438. Legne, L. Note sur une forme anomale de Collybia velutipes 

 Curt. (Bull. Soc. Myc. France, XXV, 1909, p. 119—122, 1 fig.) 



Beschreibung und Abbildung einer morchelloiden Monstrosität der ge- 

 nannten Art. 



