PART V. 



REPRESENTATIVE FAMILIES OF ANGIOSPERMS. 

 CHAPTER LVIIL 



RELATION OF SPECIES, GENUS, FAMILY, ORDER, 



ETC* 



1133. Species. It is not necessary for one to be a botanist in 

 order to recognize, during a. stroll in the woods where the tril- 

 lium is flowering, that there are many individual plants very 

 like each other. They may vary in size, and the parts may 

 differ a little in form. When the flowers first open they are 

 usually white, and in age they generally become pinkish. In 

 some individuals they are pinkish when they first open. Even 

 with these variations, which are trifling in comparison with the 

 points of close agreement, we recognize the individuals to be of 

 the same kind, just as we recognize the corn plants, grown from 

 the seed of an ear of corn, as of the same kind. Individuals of 

 the same kind, in this sense, form a species. The white wake- 

 robin, then, is a species. 



But there are other trilliums which differ greatly from this one. 

 The purple trillium (T. erectum) shown in fig. 537 is very different 



* Chapters XXXVIII-XLV should be studied in connection with the 

 following lessons on families of the angiosperms (in Chapters LIX-LXV). 

 but especially should Chapters XLII, XLIII, and XLIV be consulted. 

 See also Chapter LXVI for the arrangement of families, orders, etc., in 

 classification. See also "Suggestions for the teacher," foot of page 349, 

 Chapter XXXVIII; see also Chapter LVII. 



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