494 



centre showing the strongest action. The vine leaves showed a number of 

 spots, which at first appeared dark green and after several days turned 

 brick red. In the younger sappy stems, especially the cambium had turned 

 brown, while the wood was uninjured. In the injured tissues, the cell walls 

 remain unchanged, but the protoplasm was contracted and killed. Rathay^ 

 has described the same obser\'ation of the distribution of the eflfect of light- 

 ning on numerous individuals and, after mentioning earlier cases, also refers 

 to the fact that the same phenomenon of the spreading out of the lightning 

 is observed in sheep herds, where likewise several individuals were always 

 hit.- 



Like Colladon. Rathay also ol)ser\ed that the leaves became red in 

 varieties whicli sliowcd a red autumnal coloring. All the ends of the 

 branches died back. The process of the red coloration in leaves has already 

 been determined by Wiesner and by me as a result of ringing and bending 

 experiments. Rathay supplemented this by observing that the reddened 

 leaves transpired much less than normally green ones. Leaves reddened 

 after having been struck by the lightning, resembled, in all particulars as yet 

 tested, those which turned red from ringing the branches and actually the 

 injury from lightning resembled in many points mechanical girdling, since 

 here the bark lying outside the cambium was killed. "The cambium of the 

 I)arts struck by lightning remains alive and develops inside the dead tissue, 

 toward the outside, a callus surrounded by wound cork and. toward the 

 inside, a woodring which is separated from the older wood by a fhin brown 

 layer." The grapes on the vine struck by lightning dried up absolutely. 



We find in a work by Ravaz and Bonnet- different points of importance, 

 showing parallelism between the efifect of lightning on grapevines and on 

 conifers. After calling attention to the fact that a place struck by lightning 

 which was planted with 50 to 100 vines, showed that the strongest plants 

 were much injured, it should be emphasized that, after being struck by 

 lightning on the 20th of May, the tips of the shoots turned down toward the 

 ground and dried up. The nodes remained green for some time, while the 

 internodes looked almost scalded. The phenomenon of disease gradually 

 decreased toward the bottom. Below the dried tips, the pith was torn in 

 the injured young shoots and pressed against the woodring. The roots 

 remained uninjured. Some weeks after having been struck, the injured 

 internodes appeared a reddish brown, shrivelled and cracked longitudinally. 

 The tears showed a scar tissue. The intermediary nodes were strikingly 

 swollen. Where the tips had not been struck, the branches grew further, 

 but had very short internodes. The young wood tissue appeared brown 

 and its cells empty and with unthickened walls. The injured parts of the 

 bark were enclosed by cork so as to form island-like structures (compare 



1 Rathay, Emerich. iJber eine mprkwiirdige durch den Blitz an Vitis vinifera 

 hervorgerufene Erscheinung. Denkschr. d. math.-naturwiss. Klasse d. kais. Akad. 

 d. Wissensch. Wicn 1891. Extensive biblioiarraphy here. 



2 Ravaz, I^. ct Bonnet, Effects de la foudre sur la vigne. Extr. des annates de 

 I'ecole natjonale d'agricult. de Montpellier; cit. Bot. Jahresb. 1900, II, p. 417, 



