BRIEFER ARTICLES 143 
€a, would be needed to make conclusions of any value. From the 
eather Bureau reports at our disposal from stations from Milwaukee 
© Dubuque, some of them going back to 1871, it does not appear that 
here has been any significant change. The last decade includes dry 
years and wet years, dry and wet summers. 
_ The influence of deforestation on the character of the flora is another 
teresting subject. While the relative representation of different com- 
onents of the flora has of course changed profoundly, remarkably few 
lants have as yet become extinct. No tree has certainly disappeared 
ithin thirty years. We have the only local herbaria of any size, that 
Herbert E. Copeland dating from the early seventies, and our own, 
‘Mostly about seventeen years later. The only plants whose disappear- 
ance in that interval is highly probable are Camassia Fraseri and Pogo- 
ma pendula. In the last fifteen years Cypripedium spectabile, Gaultheria 
cumbens, Phegopteris Dryopteris, and possibly as many more plants 
ll strictly local, seem to have been killed out. On rare rough hillsides 
1 in gulches where the timber is relatively native, and in fence cor- 
ers, in brush, or around stumps, the old flora persists. It is a most 
nstructive lesson in the survival of what exists that above thirteen- 
. 
er, and the other one-fourteenth decidedly modified, without the 
xtinction of a single common forest herb, shrub, or tree—F. A. 
RINER and E. B. Cope.anp, Monroe, Wis. 
THE EFFECTS OF EXTERNAL AGENTS ON THE 
PRODUCTION OF ROOT HAIRS. 
PRELIMINARY NOTICE. 
Durine an endeavor to find the causes for the production of root 
irs, results were obtained, which, though incomplete, may be of suffi- 
ent interest to warrant publication. 
Seedlings of Zea mais, Helianthus annuus, Lupinus albus, Avena 
tiva, Triticum vulgare, Vicia sativa, Cucurbita Pepo, Raphanus sati- 
tS, Brassica alba, and Cannabis sativa, grown in water, showed a ten- 
ney 1 not to develop typical water roots at once, but produced a 
ger or shorter zone of hairs, passing, in some forms, into the smooth 
rface usually characteristic of water roots. Apparently this zone of 
in sunflower, radish, and white mustard was not directly influenced 
ight or darkness. 
