( 48 ) 



The observation may here I)e inserted, that Ave speak of cliance 

 in natnre, Avlieii small variations in the initial data occasion consideralile 

 variations in (lie (inal elements, because we cannot oliserve tliosc^ small 

 variations, ('vclic motions foi- instance will also alwavs ,£>ive rise to 

 such cases. 



For tli(^ special case coiisi<lere(l liei-e the resnlt we liav(> found 

 may be formulated ;is follows: \\]\r\\ in a j»urely mechanic. i-e\('rsibl(> 

 [►rocess Avhicli occurs a ixwai many times in the same way, events 

 occur in which small variati(Mis in the initial data occasion considerable 

 vai-iations in the final state, then the total process gets the proj)erties 

 of ail irrexersible jtrocess. 



Botany. - "On u SclcrohnKi liillnrhi niiLinnm kikJ i/ij/ir/dns /a tlir 

 riiltirdlnni tij' lithaca).'^ (Sc/('n>/////(t X/Cd/id/iifc ()[ i). o\ Komno). 

 {\\\ Prof. ('. A. J. A. OiDKMANs and Mr. ('. .1. Komm;). 



The followinu' (•oiumuiiieation conlains fixe jiaraiiraphs. 



/'(If. I ,<ii\es an account of a visit to the tobaccofields in the 

 \'eluwe and IJetnwe, in the autumn of 1902, about the time that 

 the t()l)accoleaves bejiiii to be gathered. 



I*<ii-. II contains an iii\-esliiiatioii of the disease which had atlacke(l 

 the j)lants, e\i(lenlly a funjius, which had loiii;' been known as 

 "Rot", but the nature of which lia<l not yet been cleared up. 



I*(ir. Ill nives a summary of the experiments made with (he 

 Sclerotia of the fiinuiis. 



/V/'. / r deals w ilh the anatomy of the Sclerotia and the Sc/crn- 

 Iniid ]»roduc(Ml from them. 



Par. V contains the result of some biuchemical investigations. 



I*(ii\ 17 ,^•i^■es a fcw\ hints, the application of which may |)re\'ent 

 or reduce the damage caused by Sch'rot'mid XicotidiKn'. 



1. A VISIT TO Till', TOBACCOFIELDS. 



In order to study iiuu-e closely the origin of the well-lvnown 

 patclies and specJvs on dried tobaccoleaves, one of us repeatedly visited 

 the tobaccofields in the \'eliiw(' and Betuwe in September Jl)()2. 

 These Aisits re|»ai(l the trouble \(^n'\ well indee<l. as they gave an 

 oj)portnnity of becoming ac(|uainted with an exil xvliich caused 

 much damage, had not yet been clearly defined and so deserved a 

 closer study. 



In these visits one was first of all struck by the fact that the very 

 extensive fields under cullixation Avere divided info smaller scpiare 



