88 Annals Entomological Society of America (Vol. VIII, 
(2). Necessity for generic separation of cases of parallel 
or convergent development from what are practically remote 
or very remote distinct origins; that is to say, anatomical 
parallelism or convergence in generic stems whose distinctness 
carries far back into the past, but which are in reality of ancient 
or very ancient though indirect common origin. Here the 
principles of inheritance and valuation are paramount. Here, 
if our generic concepts be not very closely drawn, they will allow 
the entrance of forms which we know positively to belong 
outside. The reproductive and early-stage characters serve 
us especially in this connection as a key to the value of the 
external adult characters. It is understood that a taxonomic 
system must neither obscure nor do violence to known relation- 
ships or lines of development, but must rather present a true 
phylogenetic picture. (See diagram). 
UNRESTRICTED | RESTRICTED 
PROFIT LOSS PROFIT Loss 
Transitional spe-|But the extremes || An intelligible gen-| But transitional 
cies are easily re-|of the genus are || eric definition may | species must be 
ferred generically| too dissimilar to || be drawn up easily | referred as lettered 
be included in an || owing to the less | subgenera 
A small number of 
generic names 1s 
required 
Correlation of the 
reproductive and 
early-stage char- 
ters with the ex- 
ternal adult char- 
ters is not required 
intelligible generic 
definition 
But a generic name 
carries no concrete 
concept of type, 
being instead an 
abstract of dissim- 
ilar forms, from 
which it results 
that generic com- 
parisons lose their 
value 
But the true rela- 
tionships and phy- 
logeny of the forms 
are obscured and 
evolutional _ pro- 
cesses ignored, re- 
sulting in miuxed- 
genera and mis- 
| identifications 
} 
number of forms 
included 
A generic name 
always implies a 
concrete concept, 
securing lucidity in 
generic comparison 
Relationships and 
phylogenetic lines 
are clearly ex- 
pressed and evolu- 
tional processes re- 
cognized, avoiding 
mixed-genera and 
misidentifications 
But a large num- 
ber of generic 
names is required 
But reproductive 
and early-stage 
characters are re- 
quired as a key to 
the phylogenetic 
value of the exter- 
nal adult charac- 
ters 
