102 APPENDIX. 



METHOD PROPOSED BY DR. KLOTZSCH, FOR THE 

 PROTECTION OF THE POTATO-PLANT AGAINST 

 DISEASES. 



" THE potato, which is an annual plant, represents, 

 in the tubers developed from the stem, the peren- 

 nial part of a plant. For while the duration of its 

 development is analogous to that of annuals, its 

 functions coincide exactly with those of dicotyledo- 

 nous shrubs and trees. 



" The potato plant differs from all those plants 

 which are cultivated for economical purposes in 

 Europe, and can only be compared to those orchi- 

 deous plants which yield salep, and which are not 

 yet cultivated among us. 



" The tubers, both of the potato and of the 

 salep plants, are nutritious, and agree in this, that 

 in the cells of the tubers, grains of starch, with 

 more or less azotized mucilage, are collected, while 

 the cell walls possess the remarkable property of 

 swelling up into a jelly, and thus becoming easily 

 digestible, when boiled with water. 



" But while the tuber of salep contains only one 

 bud, or germ, the potato usually develops several, 

 often many, germs. 



" The potato plant, like all annuals, exerts its 

 chief efforts in developing flowers and fruit. Like 

 all annuals, too, it has the power of shortening 



