1gr4f GATES—X EROPHILY 479 
Plants that were collected in the morning always had their 
stomates wide open at the time of collection. Before the laboratory 
was reached, however, the plants were frequently wilted, and inves- 
tigation always showed the stomates closed. If not too severely 
wilted, the plants survived within an hour after cutting under water 
under laboratory conditions of diffuse light. When revived, the 
stomates opened partially in the diffuse light, but opened wide 
when exposed to sunlight. 
Collections in the early afternoon of summer days were aban- 
doned because of the difficulty of getting the material into the lab- 
oratory without extreme wilting. At this time of day the stomates 
were always wide open in the field, but closed upon wilting. 
Collections made just before dark showed different results for 
different plants. The sun no longer shone upon the leaves, although 
it was by no means dark. Most of the leaves were very slowly 
penetrated by the xylol, which indicated that the stomates were 
but partially open. In some species (Nymphaea) the stomates 
were closed tight and no penetration would take place even in two 
minutes. 
Some experimentation was performed on material kept in the 
laboratory with the following results. Wilted plants (Aspidium 
thelypteris, Dulichium arundinaceum, Menyanthes trifoliata, Nym- 
phaea advena, Potentilla palustris, Eupatorium perfoliatum, Acer 
rubrum, Spiraea salicifolia, and Vaccinium macrocar pon) invariably 
had their stomates closed, as the length of time it took the xylol 
to penetrate the leaves testified. One single exception was found 
to be Salix pedicellaris, in which there was a scarcely perceptible 
increase in the time of penetration of wilted specimens as com- 
pared with plants in the field. If wilting was allowed to continue 
until the leaves became dry, the almost instantaneous penetration 
gave proof of the open condition of the stomates in the material 
used (Spiraea salicifolia, Nemopanthes mucronata, Aronia melano- 
carpa, Salix pedicellaris, Chamaedaphne calyculata, Potentilla 
palustris, Ilex verticillata, Cephalanthus occidentalis, Menyanthes 
trifoliata, Carex filiformis, and Larix laricina). Those of Gaylussacia 
baccata were only partially open. 
Leaves of Salix pedicellaris, Andromeda glaucophylla, Chamae- 
