15 
jective, and our ideas change in regard to a given case as our knowl- 
edge of the group increases. Hence, we treat generic and subgeneric 
names nomenclaturally as of the same rank and as interchangeable. 
Thus, most authors recognize that Taenia is to be divided into the 
subgenera Taenia , Multiceps (i. e. , Coenurus), and Echinococcus. Some 
authors, however, incline to recognize these subgenera as of full gene- 
ric rank. By subjecting both generic and subgeneric names to the 
same rules, and granting them equal rank from a nomenclatural point 
of view, regardless of the recognized systematic point of view, con- 
fusion is lessened, and we gradually become accustomed to associating 
certain species together in groups, to which generic rank may later be 
given. 
Art. 7. A generic name becomes a subgeneric name, when the genus 
so named becomes a subgenus, and vice versa. 
Discussion. — If an author, in revising the genus Taenia , concludes 
that the subgenera Multiceps and Echinococcus should be given generic 
rank, he is called upon to use these subgeneric names as names of the 
genera he recognizes; if a later author differs in opinion and reduces 
these genera to subgenera, he still retains the same names as names of 
his subgenera. 
This rule is based upon a fundamental principle of nomenclature too 
frequently overlooked, namely, in naming a systematic unit we name 
the object , not our concept of the object. If we name a given genus, we 
do not confine the name to the animals which come within our descrip- 
tion of the genus, but we propose a generic name to be used for all 
animals which agree genericallv with our type species, be the } 7 known 
to us or not; some later author may have a different concept of the 
extent of the genus, but as long as he classifies species genericallv 
with the species which we have designated as the generic type, our 
generic name — even if used originally in a more restricted or a less 
restricted sense — is valid, provided it fulfills all the conditions demanded 
of it by the code. 
Art. 8. A generic name must consist of a single word, simple or 
compound, written with a capital initial letter, and employed as a sub- 
stantive in the nominative singular. Examples: Canis , Perea , Cera- 
todus , Hymenolepis. 
Discussion. — It is quite a common occurrence to find in medical 
writings c c bacillus tuberculosis ,” fiC plasmodium malar iaef “ amoeba 
colif “ taenia solium etc., the generic names being written with 
small initial letter. Zoologists and botanists adopt a capital initial 
letter for the generic name, because of the aid this gives them in 
quickly recognizing the rank of the name; thus, if we find “ Hete- 
rophyesf we know that reference is made to a certain genus of flukes, 
one species of which occurs in man; if we find heterophyes used in a 
paragraph in which Heterophyes is discussed, we know that lieterophyes 
