THE COMPOSITE. 151 



much among themselves in other respects. Though 

 they all have bitter properties, yet some are tonic, 

 some acrid, and some narcotic. One group will have 

 milky juice, another will be watery and aromatic, or 

 mucilaginous, or gummy, or oily. In respect to the 

 structure of flower-heads, you have already found the 

 dandelion, with all its florets, perfect and ligulate ; 

 you found the thistle with perfect tubular florets, you 

 found the marigold with ? ligulate disk florets, and 

 tubular ray florets, the daisy with ? ray florets, 

 and <$ disk florets. Differences of this kind serve in 

 arranging this vast family into sub-families, and these 

 sub-families are again separated into smaller groups 

 by still other characters. Differences in the involu- 

 cre, and in the conditions of the inferior fruit, serve 

 to separate them into what are called genera, and 

 then the species of a genus are found to differ still 

 further in the characters of leaf and stem, in size, 

 color, etc. 



In Order VIII. of Chart II., illustrating the 

 Composite, the characters of the dandelion, thistle, 

 marigold, bachelor's-button, and globe amaranth, are 

 given ; those of the dandelion and thistle are pre- 

 sented in full detail, and much enlarged. 



