I(K)2 At^RICULTURAL BOTANY, CHKMISTRY AND l'HYSrOI,0(iY OF I'LAXTS 



other lenticels, from which and the basal area, a zone of tissue is produced 

 wliich encloses the original outer cells in which are the algae and bacteria. 

 The algal zone is continuous, except immediately below the lenticels, 

 extending from the base nearly to the meristematic apex. 



The algal zone consists of a large air-space containing Anahaena and 

 Azotobader which is kept intact by papillate cells traversing it from both 

 the inner and other tissues. Bacillus radicicolais chemiotactically attracted 

 to the algal zone, thus leaving the cortical cells in which large quantities of 

 starch grains and sphaeraphides are deposited, and in Dioon, also tannin. 

 No algal zone has been observed in Macrozamia, Zamia, Ceratozaniia, and 

 Bowenia, but nodules are produced by Bacillus radicicola and Azotobacter. 



The Cycadaceae, a group with many primitive characters, are the only 

 nodule-bearing plants known, in which four organisms are associated to- 

 gether symbiotically, viz. two nitrogen-fixing bacteria, an alga, and the 

 cycad. 



A bibliography containing ii references is appended. 



850 - The Enzymes Zymase and Carboxylase in the Storage Organs of the Potato and Su- 

 gar Beet. — BodnAr J. (Chemical I^aboratory of the Royal Hungarian Station of Plant 

 Phj'siology and Pathology, Budapest), in Mathematikai is Termcszettudomdnyi 6,rtesito 

 (Bulletin of Mathematics and the Natural Sciences), Vol. XXXIII, Parts 3 and 4, pp. 591- 

 610. Budapest, 191 5. 



After reviewing the work of Buchner, Stoklasa, Neuberg, Maz6, 

 Pai,i,adin and Kostystchew, etc. the writer sets out his experiments in 

 detail (summarised in several tables) as carried out on the tubers of several 

 varieties of stored potatoes and on specimens of thoroughly ripe sugar beet. 



Conclusions : i) Zymase can be isolated from the storage organs of 

 the potato and the sugar beet. These results agree with the observations 

 of J. vStoklasa. 



2) Even though in some cases there were bacteria in the ferment- 

 ing liquid obtained, they did not exhibit the property of splitting up glucose 

 in the presence of 2 pei cent toluol, in the manner characteristic of alco- 

 holic fermentation. 



3) The enzyme extracted from the tuber suffering from the disease 

 termed by Appei. " Bakterien-Ringkrankheit " (i) acts on the solution of 

 glucose in such a way that in the fermenting liquid only traces of alcohol 

 can be detected. On the other hand, there is found the presence of an ex- 

 cess of acetic acid due to the action of the soil bacteria (producing alcohol- 

 oxidase) on the alcohol formed by the activity of the zymase. The bacte- 

 ria of the soil had entered in the spore form into the enzyme extracted 

 from the diseased tubers. 



4) Under the action of the enzyme isolated from sugar beet suffer- 

 ing with bacillary gummosis, carbonic acid and alcohol were produced in 



(i) Cf : O. Appel, Die Bakterien-Ringkrankheit der Kartoffel, in Fhi'^hlatt 36 der Deutschcn 

 Kaiserlichen Biologischen Anstalt Dahlem, igo6. — P. Sorauer, Handbuch der Tflttnzenkrnnkhci- 

 tcn, 3rd edition, Vol. I, pp. 398-399. Berlin, Paul Parey, ed., 1909. 



