542 FETCH : 



(/) Undififeiontiated tiBsuo from the bud : spores sown on 

 the cut surface. No growth in seven days. This 

 piece developed two colonies of Sterigmatocystis , one 

 colony of Mucor stolonifer, and seven colonies of 

 Pestalozzia 'palmarum. 



(g) White tissue from the centre of the stem. Good growth in 

 two days, chiefly macroconidia,withafewmicroconidia. 



This series of experiments shows that Thielaviopsis grows 

 luxuriantly only on the stem tissues of the coconut. Its 

 failure to develop on the immature bud tissues agrees with the 

 observed fact that the disease, even on trees which have been 

 hollowed out by it for several years, does not extend into the 

 bud. Analyses by Mr. A. Bruce show that none of the tissues 

 employed contain free sugars except the stem, and even there 

 the amount is small. It would appear, therefore, that the 

 growth of Thielaviopsis is governed by the amount of sugar 

 available. If the tissue of the leaf stalk is boiled, sugar is 

 obtained in abundance, probably from glucosides ; apparently, 

 therefore, Thielaviopsis is not able to make use of this combined 

 sugar. 



The Need of Oxygen. 



As the fungus grows and forms conidia within the tissues 

 of the coconut and sugar cane, the effect of depriving it of 

 oxygen was tried. 



Two sterilized watcli glasses were filled with sugar cane 

 extract, and placed on glass supports under bell glasses 

 standing in glass dishes. Spores from the same cultures were 

 sown in each. A was isolated from the room atmosphere by a 

 water seal, and the oxygen in B was absorbed with pyrogallic 

 acid and caustic potash. There was a cojaious growth of 

 Thielaviopsis in A after three days, but no growth in B at the 

 end of a week. The spores and sugar solution from B were 

 then transferred to a sterilized flask, where Thielaviopsis 

 appeared and attained the macroconidial stage after one to 

 two days. 



Growth in Light and in DarJcTvess. 



In each of two 150 c, c. conical flasks, 50 c. c. of the same 

 sugar cane extract was placed, and the flasks were inoculated 



