Physiologie. 347 



fungi on or in seeds, and of course the presence ofseedscontaining 

 dead embryos. 



Hard-coated seeds of legumes, and seeds of Delphinium, Ipo- 

 moea, lettuce, mustard, okra, sweet marjoram, and snapdragon 

 can be forced to more rapid germination by being blown against 

 needle points. 



For two varieties of lettuce it is shown that the seed improves 

 in viability as it grows older, up to the end of at least the fourth 

 year. This improvement is probably due to increased permeability 

 of the inner seed coat to water. 



Cold storage in wet sand increased the germination of seeds 

 of Pinus Strobus by 32 per cent, of Cupressus macrocarpa by 

 31 per cent. Delayed germination of conifer seeds, more especially 

 those of Pinus Strobus and P. austriaca, seems to be due to lack 

 of water intake, and not to an alkaline or neutral reaction of the 

 embryo. This Statement is supported by the fact that seeds injected 

 with distilled water gave better germination than those merely 

 soaked in water or in weak acid at the temperature of melting ice. 

 Any kind of soaking or injection gave 13—38 per cent better germi- 

 nation than was obtained with the controls. 



Certain samples of frosted oats improve in germinating power 

 as they grow older, others deteriorate. 



Certain late varieties of western-grown garden peas germinate 

 poorly. This is shown to be due to one or both of two causes : 

 a. actual frost injury to the embryo; b. the presence of fungi on 

 or in the seed coat or inside of it. 



Seeds of 51.4 per cent of all species and varieties examined 

 showed fungi on the seed coat within two days after being put to 

 germinate. Jongmans. 



Rose, D. H., Oxidation in healthy and diseased apple 

 bark. (Bot. Gazette. LX. p. 55-65. 1915.) 



Extract of apple tree bark affected with Illinois canker, 

 caused by Nummularia fi?/scre?«(Schw.)Tul., causes greater and more 

 rapid oxidation of pyrogallol than does the extract of healthy bark. 



Diseased bark extract is less acid than healthy bark extract, 

 according to both indicator and titration figures, hence the conclusion 

 seems justified that oxidation is in approximately inverse ratio to 

 the acidity of the extract in the ränge of concentrations here used. 



This conclusion is borne out by the fact that addition of acid 

 to the Solution in the apparatus decreases oxidation and addition 

 of alkali increases it. 



Oxidases are very sensitive to small variations in aciditj^ of 

 the Solutions in the oxidase apparatus. 



As a hypothesis in need of further proof the followingisoffered. 

 The gradual slowing down of oxidation in the Bunzelapparatus is 

 brougt about by accumulation of oxidation products, probably acetic 

 and oxalic acids, and not by a using up of the oxidase through 

 Chemical combination between oxidase and oxidizable substance. 



' Jongmans. 



Tpöndle, A., Ueber die Permeabilität der Wurzelspitze 

 für Salze. (Actes soc. helvet. sc. nat. 97me sess. 1915 ä Geneve. 

 p. 203-205. 1916.) 

 Die embryonalen Zellen der Wurzelspitze von Lupinus albus 



