348 BOTANICAL GAZETTE [MAY 
for long periods. The injury in this case must be stated in terms 
of the region and extent of killing. The records were taken five 
days after the mishap. : 
The following showed no injury: Bryopnytes, Marchantia 
polymorpha, Conocephalus conicus (not under spray); PTeERI- 
DOPHYTES, Cyrtomium falcatum, Azolla caroliniana, Salvinia natans; 
SPERMATOPHYTES, cycads, when not actively growing (Dzoon edule, 
D. spinulosum, Zamia floridana, Macrozamia Miquelii, Encepha- 
lartos cycadtfolia, E. Lehmanit, E. Altensteinit, E. horridus, E. caffer, 
and Ceratozamia mexicana), Hibiscus rosa-sinensis, Zebrina pendula, 
Begonia semperflorus (flowers and foliage), Pelargonium zonale, 
Ficus elastica, F. lyria, Sagittaria variabilis, and Lemna trisulca. 
The following forms showed evident injury: BRYOPHYTES, 
Riccia (in pots on benches, all killed), Conocephalus conicus (grow- 
ing under spray, all killed); PrertpopuHytes, Lygodium sp. (leaves 
all killed at tips and margins and many halfway back), Pteris 
longifolia cristata (tips and margins of leaves killed, brown spots on 
leaves), Nephrolepis bostoniensis (slight injury), Aspidium longi- 
folium and A. nidus (some of the plants killed to the ground), 
Alsophila denticulata (badly injured); SPERMATOPHYTES, Impatiens 
Balsamina (all the older leaves brown-spotted), tomato (leaves 
entirely killed in most cases, but only at the tip in some), Persia 
gratissima (older leaves all killed), Stevia serrulata (all but youngest 
leaves killed), Vinca alba (ends and margins of leaves slightly 
injured), Coleus spp. (all older leaves fallen, young plants showed 
less injury). It is of interest that Conocephalus conicus growing on 
the benches was not injured at all, while a vigorous culture that had 
been growing for a long period under a spray was completely killed. 
It is possible that good water supply caused the development of a 
loose, poorly protected structure. It is likewise possible that the 
great surface of the spray water kept it nearly saturated with the 
poison of the smoke. From the data given above, one can see that 
in general the better cutinized forms are more resistant. Some will 
be interested in comparing these injuries with those from illuminat- 
ing gas observed in a greenhouse by Witcox (44). There is evi- 
dence to indicate that both injuries are due to a common substance, 
as we willsee later. In the case reported by Witcox, the poisoning 
