INJURIOUS EFFECTS OP ILLUMINATING GAS. 



285 



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Figure 11. Carnations three weeks after injury. 



having plants injured in this manner. Many small stock geranium plants 

 were killed outright, though a few show recovery by the formation of 

 small shoots from near the surface of the ground. Figure 6 shows the 

 extent to which one of these geranium plants was injured and figure 7 

 shows the new shoot forming near its base after about three weeks. 



Lilies, both Lilium giganteum and Lilium mutiflorum, were practically 

 killed outright or so far stunted in their growth as to have no value at 

 all. (Figures 8 and 9.) 



Clivias showed complete defoliation as is well shown in figure 10. 

 -Absolutely new shoots are. however, appearing and the figure shows their 

 size at the end of about three weeks. Narcissus showed a very peculiar 

 form of injury so far as the leaves were concerned. The tips of these 

 leaves became curled up and at the same time assumed a purplish hue. 

 At the same time open flowers were killed outright and in the case of this 

 plant many of the roots now show considerable injury. The outer leaves 

 of the Agave were killed at their tips or in some cases to the bottom. 

 In fact one of the very chacteristic effects of illuminating gas is the 

 injury it does to the older leaves of plants. This was well shown by 

 such plants as Pandanus, Zamia, Aroides or Calla lily, Abutilon, etc., in 

 addition to those mentioned above. 



A further fact of interest to the pathologist as well as the professional 

 florist is the apparent increase in the amount of carnation rust following 

 this gas injury. Such gas-injured carnations (Figure 11) are often said 

 by florists to be "sleepy" — it is possible that in this asphyxiated condi- 

 tion they are not as resistant as normally to the attacks of various 

 parasitic fungi. Some further technical discussion of some of the prob- 

 lems raised by this matter are reserved for publication in another place. 



