THE NAMING OF ROCKS 693 
It is also self-evident that the extreme refinement practiced 
by Washington and Cross is in no respect lost by using the 
nomenclature proposed, rather than assigning independent names 
to particular varieties of rocks described. Indeed, the com- 
pound names proposed give additional refinement to that attained 
by independent names. 
In giving the above illustrations I express no opinion as to 
whether the various syenites, trachydolerites, and leucite-tra- 
chytes are so abundant and important as to be worthy of specific 
names. This is a matter for the petrographer to settle. I 
merely use these terms as convenient illustrations as to how rock 
nomenclature can be handled so as to serve the purposes of the 
general geologist and the specialist, without throwing the sub- 
ject of petrography into hopeless confusion. 
Objection to long names.—The long terms resulting from the 
plan, as, for instance, augite-toscano-trachydolerite, may be 
objected to on account of their cumbersomeness and complexity. 
However, it may be said that these names are simple as com- 
pared with many of the names used in organic chemistry, and 
furthermore that they are justified on precisely the ground 
that the long names in organic chemistry are justified, that ts, 
they are intelligible names. This is the fundamental point. The 
present method of naming rocks is not intelligible even to pro- 
fessional petrographers, and an unintelligible method can no 
longer be tolerated. The method proposed is intelligible to 
every geologist, whether a specialist in petrography or not, and 
gives at once the information desired by the general geologist 
and the extreme refinement demanded by the petrographer. The 
plan proposed gives all the advantages of generic, specific, and 
varietal names. If any petrographer can suggest a method of 
naming rocks which will better satisfy the demand of the petrogra- 
pher for exactness, and of the geologist for intelligibility, I shall 
gladly favor such a plan rather than my own proposal. 
Why petrographers have not generally followed plan outlineda.— 
The plan suggested is so simple that the question immediately 
arises as to why petrographers dealing with igneous rocks have 
