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128 THE CONDOR Vol. XXIII 
The limits of a group can be stated only in relative terms. A species is one 
kind of an organism, but the degree or the quality of difference that shall sep- 
arate one species from another cannot be stated. A genus is a group of closely 
related species, but no one can say how closely they must be related. Even  \, 
the individual is but a phase in the great organic stream and is intimately 
connected with its parents and its offspring. If we had before us all of the 
expressions of life that have been, who could venture to designate genera and 
species? When we say that a species is well marked, we mean that we are 
ignorant of its close relatives, which may be living or fossil.. While we are 
defining a species, it becomes something else. The present is gone as we say 
it and has become the past. In practical taxonomy, of course, we treat genera 
and species as if their characters were fixed, and fortunately most of the 
species of taxonomy differ enough so that they can be easily recognized. 
I have long believed what Doctor Stone points out; namely, that we try 
to make our system of nomenclature do double duty and that this is an ‘“‘impos- 
sible burden’’ or, at least, it is an attempt to force on the generic name a 
function for which it is not fitted. I have also hadin mind to suggest exactly 
the remedy proposed by Doctor Stone; namely, the reduction of the weaker 
so-called genera to the status of subgenera. My idea is that these subgenera 
are useful in keys to show the grouping of species in large genera. 
Some botanists follow a practice that appeals to me as being very service- 
able in connection with genera containing many species; this is the use of the 
section, in effect the subgenus. The name of a section is placed after the spe- 
cific name and is used only when it is desired to show the position of the 
Species in the genus. An illustration of thisis found in the names of the plants 
that are commonly called begonias. There are several hundred species assigned 
to the genus Begonia, and probably as many more remain unknown to science. 
The species fall into several groups that many zoologists would certainly rec- 
ognize as genera. How many botanists do so I do not know, but the more con- 
servative among them resort to the use of sections when they wish to designate 
a part of the genus Begonia. As Doctor Stone points out, this retention of 
generic names in the broad sense is of assistance to those who are not special- 
ists in the particular group; at the same time much of the transferring of 
specific names from genus to genus is avoided. © For example, begonias are so 
well known as cultivated ornamentals that any reader would have some con- 
ception of the kind of plants indicated by the scientific names Begonia pseudo- 
lateralis, Begonia mindanensis, and Begonia luzonensis. If the section names 
were given generic rank, the same begonias would appear as Sphenanthera 
pseudolateralis, Petermannia mindanensis, and. Diploclinium luzonensis. 
Another method of dealing with the subgeneric name seems to be popular 
with some entomologists and others—the subgeneric name is inclosed within 
parentheses between the generic and the specific name. For example, 
Colymbus (Dytes) auritus, for the horned grebe. This style leads to unpleas- 
ant remarks on the part of the indexer, but no one considers his convenience. 
Some systematists are inclined to give little consideration to the needs 
of the student of anatomy, geographic distribution, or general biology. In 
effect they say: ‘‘Only a specialist can judge of the validity of a genus or 
species.’? The general zoologist cr botanist respects the work of the taxo- 
nomist and systematist and must take the classification and nomenclature of 
