24 PARASITES BELONGING TO THE GENUS GLOMERELLA. 



CULTURES FROM ASCOSPORES. 



On June 25 poured plates were made with ascospores taken from a 

 portion of a leaf in moist chamber which was producing perithecia 

 only. A single ascospore was isolated and transferred to a slant agar 

 tube. 



On July 22 one plate showed a few perithecia with immature asci. 

 No conidia were found . The tube culture from a single ascospore devel- 

 oped only a hyaline sterile mycelium and chlamydospores. Transfers 

 from this tube to corn-meal flasks produced an abundant growth of 

 white mycelium, which later became pinkish. On July 22 a very few 

 spores, apparently conidia, were found. No typical acervuli or perithe- 

 cia were produced in these cultures and it might possibly be suspected 

 that the ascospores used did not really belong to Glomerella. They 

 were, however, typical in appearance and morphological characters, 

 and their identity could scarcely be doubted. The cultures from the 

 ascospores on pomelo leaves did not produce, as is usually the case, 

 many ascogenous fructifications. Only a few perithecia with spores 

 were produced. Conidia were also scattered. No setae were found, 

 but chlamydospores were usually present. The ascospores from 

 leaves in moist chamber varied from 18 to 23 by 4.5 to 6 /*. Asci were 

 60 by 10.5 to 12 fi. Paraphyses were found. The conidia from 

 these cultures varied from 12 to 24 by 5 to 6 /£. Conidia from the 

 leaves in moist chamber varied from 13.5 to 21 by 4.5 to 7 [x. 



CITRUS LIMONUM RISSO. (LEMON). 



Glomerella cingulata (Stonem.) S. and v. S. 



DEVELOPMENT ON LEAVES IN MOIST CHAMBER. 



Leaves of lemon taken from a plant in the greenhouse and showing 

 small discolored dead spots bearing a few conidia were placed in a 

 sterilized moist chamber. An abundance of acervuli soon developed 

 over both surfaces of the leaves. A few setse were found. No peri- 

 thecia were produced on these leaves. 



On January 29 another leaf spotted in the same way and showing 

 acervuli was placed in a moist chamber. On February 19 the leaf was 

 almost covered with acervuli. A few setae were present. A few 

 areas bore perithecia agreeing in every respect with those found on 

 leaves of other citrus species under similar conditions. 



On January 29 three leaves apparently perfectly healthy were 

 sterilized as usual and placed in a sterile moist chamber. On Febru- 

 ary 11 acervuli were present on the largest leaf, occurring mostly 

 along the midrib and the larger veins. On February 15 this leaf had 

 grown much darker and many acervuli were present. The other two 

 leaves showed no signs of a fungus except that the petiole of one bore 



252 



