134 APPLIED BIOLOGY 



It is obvious that the advantage of the double name is 

 the same as in a human family. The names Smith, Jones, 

 etc., designate families ; but we must have a second name, 

 such as John, Thomas, etc., to indicate individuals. Like- 

 wise in biology, names like Viola serve as family names to 

 include all closely related animals or plants, and a second 

 name is needed to distinguish the different kinds of violets. 

 In writing the scientific name we put the family name first ; 

 but we also do the same thing with human family names 

 when making an alphabetical list of names, as for example in 

 a biographical dictionary like " Who's Who in America." 



But why should scientific names not be in English, as for 

 example, violet sweet, violet yellow, and violet lance-leaved, 

 placing the family name in English form first and adding a 

 second name to distinguish different kinds of violets? The 

 answer is that scientific language must be cosmopolitan so 

 that students in any language can understand ; and so it has 

 been agreed to base scientific names on the classical languages, 

 making the names Latin in form, and largely of Latin and 

 Greek words. Viola tricolor (violet three-colored) is under- 

 stood all over the world among scientific men as meaning 

 the plant which we call pansy, which some people call " heart's 

 ease," and for which there are other local names in many of the 

 languages of Europe. 



Many of the scientific names are simply the Latin name. 

 For example, Bufo americanus is Latin for American toad, 

 Phaseolus vulgaris for common bean, Felis for cat, and 

 Canis for dog. Sometimes the words are descriptive, e.g., 

 all the second names of violets mentioned above, Sanguinaria 

 referring to the juice of blood-root, and Hepatica to the shape 

 of the leaf of that plant. Some names are in honor of the 

 discoverers of certain plants or of prominent botanists ; e.g., 

 the spring-beauty, Claytonia, was named for Clayton, an 

 early botanist; and Viola brittoniana is a species of violet 

 named for Professor Britton, the director of the New York 



