406 Agricultural Experiment Station, Ithaca, N. Y. 



quite a compact association of irref^ular cells. The black color of 

 the pustules comes fi-om the sti"Oina.. 



Following the analogy of other authracnosi^ thc^e .spores falling 

 upon other stems would spreatl 11h^ disease'. The ])ra("tical qiKf?- 

 tion is, of course, how to prevent the isprea<i of the fungus, or tJie 

 starting of the disease another year. The suggestion might be 

 made to trim the hedge with the shears below the altected ]>arts 

 of twigs and bum tie trimmings. It miglit also be well in. Mic 

 spring jiLst before the buds swell to llioroughly spi-ay the h(-dge 

 with the Boi'deaux mixture to kill any si^orets wliich may have 

 remained during the winter. 



Method of separation of the fungus. — To study the development 

 of the fungus it w{i« necx?ssiiry to separate i( from oHkm- coninKm 

 fonus of fungi as well as bacteria which always tind a, loilgment 

 in and vipon dead phmt tissue. Since all tlusse foi ins are mici^o- 

 scopic the separation involvt^ a method of ju-oci'dun- laniiHar only 

 to s]vecialists, and as such beautiful n\sults wer;- i-cachcd in tlii' 

 separation of this fungus it suggested a graphic presentation of the 

 method in connection with the study. The method used was 

 tlieeameas that which Kcn-h develope<l so admirably l(tr the sepa- 

 ration of iMicteria, and consists in the dilution, of l.lie. organisms 

 in several quantities of a wann licpiid subKitantn' which, wht'U 

 spread out in a thin layer and cooled, solidifies and holds eaclu 

 germ firmly fixed at one jioint in the dilution. This substance is 

 usually some gelatinous base,. as gelatine, or agar-agar, containing 

 beef broth and peptone to furnish food for the organisms. In a 

 few days after cooling the dilutions in the tliin biyer each f^Qi-an 

 by growth has produced a colony wliich can be mnm with the 

 unaided eye. 



Three glass tubes containing a small (piantily of Uquid nutrient 

 agar-agar were placed in a wnUiV bath at 43 degrw-s centigrade. 

 This temperature is sufiticient t-o keep the agar liquid, while 

 it is not hot enough to kill tlu^ organisms. Now sevea-al thin 

 shavings thi-ough the fungus pustules on the stem of the privet 

 were transferred to tube No. 1. This was shaken gently to dis- 

 tribute the germs evenly through the liquid. Now a small quan- 

 tity of the liquid in No. 1 c(mtaining the germs was transferred 



