STYLE AND SUBSTANCE 477 
I entirely agree with all you say about representative 
species, and groan over the hitch in deciding what we are to 
agree to call a species in such cases. I also fully agree that 
the fundamentality of the argument derived from generic 
resemblance is not fully appreciated by myself ; one is apt 
to overlook its real whole weight, from being accustomed 
to bear it, hke atmospheric pressure. It is per se unanswer- 
able, and hence put aside for less valuable facts that afford 
scope for reasoning and debate. I am hence the more glad 
that I wound up my chapter with the quotation from you ; 
for which I do not deserve the credit which I hope others 
will attach to its introduction. I put it in as much for the 
sake of strengthening my argument by quoting one known 
to be so able to judge as you are, as for what it said. I 
beheved in you in short, quite as much as in what you 
wrote. 
To Asa Gray 
March 29, 1857. 
My Father has just asked me to review Berkeley's Intro- 
duction to Cryptogamic Botany for him a httle in detail. It 
is no joke to read it to begin with. It is a wonderful book, 
chock full of observations, full of reflections, full of able 
thought, accurate analysis, as carefully and honestly done 
as a book can be, and a result of a mastery of the subject 
which I believe no other man living possesses. Unfortu- 
nately it is abominably written and arranged, and the really 
admirable correlations of facts and phenomena in the 
different organs and orders of plants dealt with in the most 
higgledy piggledy fashion. It is hke a country parson's 
sermon all over, without a beginning, middle, or end, the 
leading ideas are here, there, and everywhere, bound together 
by the jolhest rigmarole of conjunctions, prepositions and 
adverbs. These parsons are so in the habit of deahng with 
the abstractions of doctrines as if there was no difficulty 
about them whatever, so confident, from the practice of 
having the talk all to themselves for an hour at least every 
week with no one to gainsay a syllable they utter, be it ever 
so loose or bad, that they gallop over the course when their 
field is Botany or Geoloizy as if we were in the pews and 
they in the pulpit. 
