Fungi, Bacteria und Pathologie. 17 



SH!BATA, K., Die Enzym bildung in schrumpfkranken 

 Maulbeerbäumen. [Vorläuiiire Mitteiluni?.] (The Botanical 

 Magazine, XVII. 1903. p. 157^.) 

 Verf. stellte eine Reihe von vergleichenden Versuchen über 

 die Enzymbildung in den Vegetationsorganen der schrumpf- 

 kranken und gesunden Maulbeerbäumen an. Es wurde fest- 

 gestellt, dass der Gehalt der schrumpfkranken Laubblätter an 

 Diastase, Invertase und Oxydase immer bedeutend grösser ist als 

 der der gesunden. Die Experimente lehren, dass die Mehr- 

 produktion der Enzyme in Laubblättern durch die gehemmte 

 Entleerung der Assimilate hervorgerufen wird, was thatsächlich 

 bei den schrumpfkranken Laubblättern der Fall ist (Miyoshi). 

 Es wurde weiterhin gezeigt, dass die Diastasewirkung nicht 

 durch die Oxydase verhindert wird, so dass der letzteren keine 

 ätiologische Bedeutung zukommt. Die ausführlichere Arbeit 

 wird demnächst erscheinen. K. Shibata. 



Smith, Ralph E., T h e W a t e r - R e 1 a t i o n o f Puccinia Asparagl. 

 (Botanical Gazette. XXXVIII. p. 19—43. 21 fig. Jul. 1904.) 



The writer summarizes the results of his investigation of Puccinia 

 asparasi as follows : 



Direct Relation. — By direct relation is meant the effect of moisture 

 (necessarily atmospheric, except possibly in connection with the germi- 

 nation of the teieutospores, which has not been touched lipon) acting 

 directly upon the spores or mycelium of the rust. This relation has 

 proved to be of foremost importance when absolute conditions prevail. 

 It has been attempted to show: 



„That dew is of absolute necessity in infectlon by the rust and of 

 more importance than rain. 



That without moisture of this sort no infection can take place, 

 regardless of all other conditions. 



That the effects of atmospheric dryness are not limited to spore- 

 germination, but produce the following effects upon spore production in 

 cases of previous infection: Aecidial development is checked, no „Cluster 

 cups" appear, and the mycelium remains dormant for some time; if 

 moisture conditions occur, spores are at once produced, otherwise the 

 mycelium finally dies out. Uredo development is similarly checked and 

 changes to a production of teieutospores in the sori afready formed, 

 without regard to season or condition of the host; with moisture, uredo- 

 spore formation begins again at once. 



That the teleuto stage is a provision for surviving any condition 

 unfavorable to the fungus, whether of food supply, moisture, temperature^ 

 or resistance by the host^ without regard to season. 



That extremes of atmospheric moisture conditions are insufficient in 

 most sections of the country to bring out or make effective this direct 

 relation". 



Indirect Relation. — By this is meant the effect of moisture acting 

 uDon the parasite through its effect upon the host, and limited therefore 

 to soll moisture. It has been attempted to show in this respect: 



„That under any but very unusual conditions of atmospheric moisture 

 the indirect relation is of greatest importance. 



That an abundance of soll moisture during the summer has a mar- 

 ked effect in retarding the development of this fungus by giving the host 

 greater vitality and resistance. 



That this is shown by the effects of the varying summer rainfall in 

 different seasons, by the differences in the water-retaining capacity pf 

 different soils, and by the effects of Irrigation.'' G. G. Hedgcock. 



Botan. Centralblatt. Bd. XCVIII. !905. 2 



