also on roots of the following; 



75 



Aralia SiebolcLln , 

 Cerasus avitga, 

 CycLon i a vul g ar 1 s , 

 Crataegus o:syacantIia . 

 Praxinus excelsior . 

 F icus Garica . 

 Lip:ustnim vulgare^ 

 Monstera aeliciosa^ 

 Pandanus utilis . 

 Po-oulus alba. 



runus spinosa, 

 (j,uerous -ped-anculata, 

 Q.u. Suber. 



Robinia •pseud-acacia . 

 Salix Gaprea, 

 S olanum Dulcamara ^ 

 S. tuberosum 1 

 Sambucus ni^ra . 

 trimus campestris. 



According to Devaux hsrpertrophies were absent, however, 

 in shoots of, 



Araucaria Gunninghaoi 

 Abies balsamea. 

 A. , Cephalonica^ 

 ^. 'excolsa, • 

 !Buxus s emp,ervir ens . 

 Cedrus Lib;ani7 

 C rataegus Voxyacantha. 

 "cbrylus Avellana. 



Cupressus fastigiata , 

 Larix europaea , 

 Myrica Sale, 

 Pinus sylvestris'^ 



P. inaritima, 

 P. Pinea. 

 Rhus Cotinus 



Rh. Glabra. 



and on the roots of, 



Aesculus Hippocastanum 

 Castanea vulgaris , 

 Cupressus fastigiata , 

 Evonymus europaeus , 



Juglans regia, 

 Sarothamnus scoparius , 

 TJlia silvestris^ 



As Devaux himself has indicated, his reports on negative 

 results \7ill possibly need correction in a few points. It 

 (78) still re^gains worth noticing, that lenticels have not as yet 

 been caused to hypertrophy in the conifers , not even the 

 large lenticels of Gringko, T>/hich v- Tubeuf and I have also 

 investigated. 



The question of the conditions , under \7hich the lenticel- 

 excrescences are developed deserves special consideration. 



It was evident even to the earliest observers of these 

 structures that the production of the hypertrophies here 

 concerned is connected with the action of water. Thorough 

 experimental proof was undertaken first by V. Tubeuf and 

 later by Devaux. I can substantiate their results and 

 supplement them by some new observations. 



Cuttings of poplar and others, when placed in rater, be- 

 come covered v^ith lenticel-excrescences, not only on the 

 parts moistened, but also above the surface of the water, V. 

 Tubeuf has already brought up the question whether a stim - 

 ulus coming from the water is conducted upwards, or whether 

 the action of the moist air causes the production of the 



1. Devaux means the tubers. 



2, Compare Devaux, loc. cit. p., 10, 



