335 



Scrophulariaceae, Cruci ferae and, among monocotyledons, Asparagus, 

 Lilium, Orchis, Triticum. etc., and also in Equisetum. 



We think it justifiable to consider the compulsory torsion as a fasci- 

 ation which has swollen up like a barrel. The cases have no agricultural 

 significance. 



Difl^ering from them is the increased spiral twisting of normally con- 

 structed woody trunks, which we trace to an arrestment of the growth in 

 length (usually resulting from a lack of water and nourishment). 



Dropsy (Oedema). 



a). In Small Fruits. 



Since the propagation of standard gooseberries and currants by budding 

 on vigorous shoots of Rihes aureum has found wider distribution, there has 

 been a great increase in the complaints of a disease of the stock which makes 

 doubtful the success of the budding. 



This disease has been called "dropsy" by growers and consists in the 

 appearance of closed bark tumors, i. e. of bark swellings entirely covered 

 by the outermost cork layers, or of swellings rupturing later (Fig. ^o A). 

 These swellings of the bark are sometimes small, but they may reach an 

 extent of several centimeters. They are formed either on one side of the 

 trunk or surrounding it, spreading into one another. They appear most 

 abundantly on wood two or more years old, yet they can also occur in great 

 numbers on branches one year old and directly cause their death, while the 

 wood of the older branches mav become diseased, to be sure, but does not 

 directly die. 



^^'hen, as is the custom at present, Ribes is 'grafted indoors in the 

 spring, rupturing tumors are found frequently directly below the place of 

 budding. In such cases the bud does not grow. But in extreme cases the 

 same kind of swellings may also be found further back from this place, on 

 the trunk between every two buds, as well as near the buds or, rather, the 

 branches already developed from them. Cases are observed in which the 

 base of a shoot left standing on wood one or two years old, has swollen 

 up like a barrel and is covered by loose, hanging strips of bark. The branch 

 above this place is dead. 



As soon as the bark layer, which forms the outer skin of the branch 

 and covers this fresh swelling, has split, the swollen place, pushing out from 

 under it, exhibits a yellowish, spongy, soft, callus-like tissue-mass con- 

 sisting of cells, elongated to pouches, very poor in contents but rich in 

 water. (Fig. 50 i? s). This is the former normal bark of which the cells 

 beginning in the region between every two groups of bast cells (Fig. $0 B b) 

 have elongated extraordinarily in the direction of the trunk's radius at the 

 expense of their contents, otherwise rich in green coloring matter. The}' 

 have partially separated from one another, and, by their constantly in- 

 creasing extent, have finally ruptured the outermost oldest bark layers 



