How Domestic Varieties Originate 267 



suit. Seeds give new varieties; and any seedling which 

 is worth saving is thereafter multiplied by divisions of the 

 root, and the resulting plants are introduced to commerce. 



The cabbage family (see Figs. 58-64). A good illustra- 

 tion of unconscious improvement is to be found in cabbage, 

 kale, collard, borecale, Brussels sprouts, kohl-rabi, and cau- 

 liflower. These probably came 

 from a single, somewhat woody, 

 branching perennial (Brassica 

 oleracea) which is to be found 

 growing wild on limestone bluffs 

 in southwestern Europe. Some 

 are a modification of the leaf, as 

 in the cabbage and kale, others 

 of the stem, as kohl-rabi, while 

 in the cauliflower it is the selec- 

 tion of the inflorescence that 

 has caused the peculiar modifi- 

 cation. Some of these types 

 have twenty and more varieties, 

 so that there are probably over 

 one hundred distinct forms from 

 this one wild type. All of these forms are the result of long 

 and patient selection of variations that were considered 

 desirable by the gardener without any conscious attempt 

 to produce these specific forms. 



The chrysanthemum. An excellent illustration of the 

 appearing of a wide range of forms within the epoch of 

 the systematic botanists is afforded by the florist's chrys- 

 anthemum (Figs. 65-79). These chrysanthemums are now 

 so widely variable and so little referable to wild species 



FIG. 77. Hairy type. 



