682 RUBBER 



when grown in latex and in pure culture, there is a 

 distinct type of spore interpolated in the life-history when 

 the fungus is grow^n under favourable conditions. When 

 growing in latex the life-cycle is shortened by the cutting 

 out of the first stage seen in pure culture. Any shorten- 

 ing of the life-cycle may be taken as indicating relatively 

 poor conditions of growth. Therefore, undiluted latex 

 must be considered as a comparatively unsuitable medium 

 for the growth of fungi. 



(3) Black Spots in Thin Crepe Rubber. 



A yeast-like form of fungus was isolated from the 

 spots, and inoculation experiments proved this fungus to 

 be the cause. The fungus was named Chromosporium 

 crustaceum (nov. sp.). 



Comparisons of the mycelium seen in situ and in pure 

 culture showed the two to be identical, this observation, 

 therefore, supporting the inoculation experiments. 



(4) Blue-black Spotting in Crepe. 



From this spot a green mould-like fungus, Trichoderma 

 koningi (Oudem.), Oudemans et Koning, was isolated. 

 Inoculation experiments indicated that this fungus was 

 the cause of this spotting, but later observations made 

 this conclusion appear doubtful. The spot is very 

 common in this laboratory, and in later experiments 

 always appeared first upon samples of rubber dried 

 slowly, prepared from latex which had not been 

 inoculated artificially. Thus the spots developing in the 

 inoculated samples may have been due to spores already 

 present in the latex, although the controls in these 

 experiments were quite clean. 



Further observations were made upon opaque spots 

 developing in unsmoked sheet rubber coagulated with 

 acetic acid. These spots appear very common and 

 suggest bacterial colonies growing in the rubber. How- 

 ever, hyphae can easily be demonstrated in the spots. 

 There appeared to be some connection between these 

 spots and Eurotium candidum, Speg., which always 



