56 GROTE-—THE DESCENT OF THE PIERIDS. (Jan. 5, 
value. As I once said of the subgenera of Afpate/a, they serve to 
light up the subject from within. There exist genealogical twigs 
scattered up and down in literature which seem to me to have been 
drawn at haphazard, so little or no explanation is vouchsafed, and, 
on examination, so little system is displayed. But from Mr. Scud- 
der’s dangerous-looking cluster of spikes to the peaceful gulf stream 
of names which flows over Mr. Reuter’s double page, the lines can 
be followed with the help of a pin, and one feels that the opportu- 
nity is offered for pleasantly acquiring exclusive information. It 
is, however, when I survey Sir George Hampson’s phylogeny of 
the Syntomide, that the magnitude of the task before me, in pre- 
paring a similar table of the Pierid genera, becomes appalling. There 
are sO many, many, a perfect trellis work of names, all bound 
together by short and sharp lines of descent and affinity. There 
are no doubts, no uncertainties ; each title finds its exact place, as. 
in a Chinese puzzle, which, if it were to fall apart, who could put 
together again? And when I look up the couple of names I have 
contributed to this ordered espalier, I am obliged to confess that 
never, never would I have been able to get them into their present 
situation. And there is no key to the puzzle, no showing how itis 
done. Why are Metarctia, Pseudapiconoma, Zethes, so placed ? 
Why is Hyaleucerea at the bottom and Uro/asia at the top? Why 
all the names between them? Why? Why? ‘‘ Pourguoy, my 
dear knight ?’’ As inthe play, the question may be impatiently 
answered by another—‘‘ Do, or not do?’’ The idea of a genea- 
logical tree being given, the lines must be drawn in every case, to 
give an idea of completeness, of mastery of the subject, and this 
seems rather to be Mr. Meyrick’s conception and definition of 
Darwinism. 
And yet these relationships, to be symbolized by these equal 
lines, are always unequally expressed and often in nature very ob- 
scurely indicated. The leading structural peculiarity of a large 
group once seized, it is not difficult to detect this distinguishing 
feature when it occurs in a second, otherwise differing group, 
to infer thereupon the phyletic connection, assign the respective 
grade of specialization and conclude by uniting the collective names 
by aline ina diagram. With genera, when numerous, the ques- 
tion becomes one of greater detail, the interrelations grow compli- 
cated; so that, if one insists upon drawing up a complete table and 
connecting all the names, the temptation in certain places to cut a 
Gordian knot by tying one becomes correspondingly frequent. 
