160 
Bums, Regeneration and its relation to träumatropism. 
dicular. Tliey were allowed to remain in tRis position in tlie 
casts for periods ranging front twenty two Rours to ntore tlian 
eigRt days. At tlie end of this time tliey rrere released and 
grown in water or a damp atmospRere. In sixty to eiglity mi- 
nntes tlie roots sliowed tlie traumatropic curve. Tire reaction 
Aras tlie same as it would Rave been eigRt days before „Rad it 
not been Rindered by mecRanical means“.. Apparently tRe latent 
period Aras prolonged in tRe one case over eigRt days. 
Two points of view were possible. 4 ) EitRer tRe influence of 
tlie stimnlns was conducted to tRe elongating part of tRe root 
and tRere lield eigRt days or eise, tRere Avas a continual stimnlns. 
To determine tRis point tRe autRor ent off tlie Avounded area 
after tlie root Rad been in tlie casts twenty-fonr Roms and re- 
turned to tlieir casts. Tliey were finally removed from tRe casts 
and grown in water in a vertical position. Of eleven roots of 
Lupinns albus six sRowed a negative enrve bnt tRis was not al- 
Avays at rigRt angles to tRe first wonnd. Some were oblique. 
TRis metRod Rowever is open to criticism in tRat a second Sti¬ 
mulus is introduced tlie result of Avliicli it is impossible to separate 
from tlie result of tlie first. However tliis Avas only a side qnestion 
to tRe tlieme in Rand and tlie antRor dismisses it Avitli tliese 
Avords, 5 ) „tliat tRe latent period may by sncR artificial means be 
extended to more tlian a 'week is a face of sufficient pRysiological 
importance to warrant tlie more extended investigation wRicR it 
is lioped may Rereafter be given it“. 
It is Avitli tRis qnestion tRat tlie present paper deals. 
Materials and metliods. 
TRe experiments recorded Rere were conducted in tlie Arbiter 
and spring of 1902 wRen 1 was making a general study of tlie 
latent period on roots under tlie direction of Prof. F. C. New- 
combe. 
TRe experiments were conducted for tlie most part on tlie 
roots of Yicia Faba and Pisimi sativum. 
TRe Avounding Aras done witli a glass rod or by cutting. TRe 
first metRod was tlie one generally used. TRe glass rod was draAvn 
to a fine tip wliicR was lieated to redness and tRen brougRt in 
contact witR tlie growing root-tip one to one and one-Ralf mm 
from tlie tip. A feAv minutes after burning a smaü broAm spot 
conld be seen wliicR indicated tlie amouiit of tissue destroyed. 
After wounding tlie plants Avere placed first, under condi- 
tions stopping both growtR and curvature; second. otfiers under 
conditions stopping curvature only; and still otliers under condi- 
tions allowing botli. 
In every case control plants were used and an effort Aras 
rnade to work only witli strong groAA T ing plants. TRe results cited 
Arere obtained from work on a large number of roots but only a 
feAv Avill be noted in tRis paper. 
