Algae. — Eumycetes. 493 



Zum Schluss gibt Verf. noch eine Einteilung der felsbewohnen- 

 clcn Algen. Er unterscheidet zwischen epilithischen Algen, die nur 

 der Felsoberflächc ankleben, und endolithischen, die in vorhande- 

 nen Spalten (= Felsanwohner) oder selbst gebildeten Höhlungen 

 (= Felsinwohner) vorkommen. H. Klenke. 



Ewart, A. G., On Bitter Pit and Sensitivity of Apples to 

 Poison. (Proc. Roy. Soc. Victoria. XXVII. 2. p. 342-349. 1914.) 



In answer to the paper by Breidahl and Rothera in the 

 same volume, the author states that enzymes are as a rule more 

 resistant to dry and moist heat and to poisons than the protoplasm 

 of the cells containing them. Hence the diastase method will only 

 detect a poison when present in relatively large amount and m 

 soluble form, and even then only when nothing eise which affects 

 diastatic action is present in the tissue. He states that the accelerating 

 action found by ßreidahl and Rothera might be obtained : 1. If 

 a resistant and very active diastase such as Taka diastase is used 

 in relatively large amount. 2. If the tests are made at high tempe- 

 ratures. 3. If dry bitter pit pulp in which the tannic acid has been 

 oxidised is compared with fresh pulp rieh in tannic acid. 



The author replies also to a criticism that his poisoning effects 

 were due to the action of distilled water. His experiments were 

 repeated in the presence of a committee, with results similar to 

 those alread}'- published. Dilute metallic poisons produce browning 

 and pit formation in the presence of isosmotic Solutions of sodium 

 Chloride, the entry here taking place bv diffusion only. 



E. M. Wakefield (Kew). 



Graff, P. W., Additions to the Basidiomycetous flora of 

 the Philippines. (Philip. Journ. Sei. C. Bot. VIII. p. 299—307. 

 pl. 8—10. Nov. 1913.) 



Contains as new: Exidia lagutiensis, Laschia philippinensis , 

 Lentinus candidiis, L. lagunensis, Volvaria pruinosa, Naiicoria ynani- 

 lensis, and Bovista Jottesii. Trelease. 



Hawkins, L. A., The influence of calcium, magnesium, 

 and potassium nitrates upon the toxicity of certain 

 heavy metals toward fungus spores. (Physiological Resear- 

 ches I. p. 57—92. f. 1—6. 1913.) 



Quantitative studies were made of the influence of one salt in 

 altering the toxic effect of another upon the conidio-spores of Glo- 

 merella cingtilata. It was found that the nitrates of calcium and 

 magnesium modified or inhibited the toxic effects of certain lead 

 and zinc salts, but did not alter the toxicity of aluminum salts; cal- 

 cium and potassium salts likewise inhibited the toxicity of copper 

 salts. The effect of calcium upon the toxicity of copper is ofinterest 

 in connection with the problem of fungicidal action. This reduction 

 in toxicity, when found, is believed to be the result of a simultaneous 

 action of the two salts upon the organism, and not to be related 

 either to the formation of an undissociated double salt or to depres- 

 sion of ionization of the toxic salt because of the ion common to 

 the two salts. Evidence favoring this view is presented for copper 

 and calcium or magnesium. Studies were also made of the effects 



