472. The American Naturalist. [May, 
tral Arizona) blooming on July 2d under three or four inches of snow - 
which had just fallen. 
Mr. Rydberg compared some of the features presented by the sand 
region of Central Nebraska; referred to Muhlenbergia pungens and 
other so-called “ blow-out grasses” of the sand-hills; and described the 
formation of the characteristic “ blow-outs” or hollows, originating in 
spots where the grasses had died out, and deepening rapidly, sometimes 
to 300 feet, producing a country where the hills are moving every year, 
‘and where when camping he could find no fuel except roots of sand- 
cheeries exposed along fresh “ blow-outs.” 
Discussion by Dr. Allen, Mr. Wooton and Dr. Rusby followed rela- 
tive to the loco-weed poison. Mr. Wooton said that species (formerly 
Oxytropis) lambert. is the chief loco-weed about Flagstaff (Arizona); 
that cattle men claim that the well fed animal. will not touch it, but 
that those which have formed the taste will not eat anything else. 
Reasons were urged by the speakers for the belief that the results of the 
loco-weed are due simply to mal-nutrition, or to effect of seeds alone, or 
to a posion (as extracted by Sheldon) diffused in git minute quantities 
throughout the plant. 
The next paper was by Dr. H. M. Richards of Barnard College, “ On 
some of the Reactions of Plants toward Injury.” 
Dr. Richards spoke on certain effects of wounding upon the func- 
tions of various plant organs as shown by his own experiments in 
Germany last summer. Diagrams illustrating the effect of injury upon 
both respiration and’temperature were shown. In the former case it 
was seen that the respiration is greatly increased by wounding, attain- 
ing its maximum about 24 hours after the injury was inflicted ; this 
increase depending both on the stimulus of the wound itself and upon 
the access of atmospheric oxygen to the tissues. The occurrence of a 
corresponding rise in temperature, of a local nature, was also briefly 
referred to; the temperature curve corresponding closely to that de- 
scribed by the increased respiratory activity. The thermeelectric ap- 
paratus used was described ; its delicacy is such as to indicate a differ- 
ence of ¢}5 of a degree; the result with potatoes showing a maximum 
rise of temperature of a little over y of a degree at the end of the second 
day, falling to the end of the 5th day. A remarkable temperature rise 
in the onion of nearly 3} degrees was explained by the fact that here the 
rise was not local but affected the whole onion, in accordance with its 
morphological structure, and with the fact that metabolism is carried 
on very fast in the onion. 
