PART 111. 

 ANIMAL PARASITOLOGY. 



CHAPTER XV. 



GENERAL CONSIDERATIONS OF CLASSIFICATION AND 

 METHODS. 



ANIMALS that are in all respects alike we term a Species. Of course 

 the male and female of a species may be very unlike, but as a result of 

 mating they produce young having characteristics similar to the parents. 

 Now, if, as in the case of the mosquitoes causing yellow fever, we find 

 some with straight silvery lines and others uniformly showing crescentic 

 silveiy bands about thorax, yet resembling each other closely in the 

 respect of being dark, brilliantly marked mosquitoes, we should con- 

 sider them as being separate species with a certain relationship to which 

 the term Genus is applied. 



The term "genus" is of wider application than the word " species." 

 Thus animals which agree in the main characteristics of size, proportion 

 of parts, and general structure are placed in the same genus. 



In naming a species we always first write the name of the genus 

 which has a Greek or Latin name, commencing with a capital, and follow 

 with the specific term, which latter commences with a small letter. 

 Thus we designate the dark silver-marked mosquitoes as belonging to 

 the genus Stegomyia; those showing the characteristics of curved silver 

 bands and two central parallel lines (lyre pattern) on dorsal surface of 

 thorax we designate as Stegomyia calopus; the species with only the 

 straight silver lines we call Stegomyia scutellaris. 



If the specific name is a modern patronymic we add i in the case of a man or 

 ae for a woman to the exact and complete name of the person. 



Again, certain genera show resemblances which enable us to make broader 

 groupings to which we apply the term Subfamily. Thus the genus Stegomyia 

 and the genus Culex have the similar characteristics of palpi in the female being 

 shorter than the straight proboscis; we therefore classify all species of Stegomyia 



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