on trellis.par.set/get (reproducing figures from Pinheiro & Bates)

Dear R users,
I would like to exactly reproduce a figure like the 1.5 or 1.9 or 4.13 
from the book
Mixed effects models in S and S-Plus.
Not for the sake of it, but because I have my own data I would like to 
plot in that fashion
(no colors)


If I write

plot(ergoStool)

I can get a good informative plot with colors, but I would like to have 
a B&W one instead.

I've played a little with trellis.par.set
managing to change some aspect of the appearance of the plot,
for example with

prove.theme<-
  list(
       dot.line = list(col = 1, lty = 3, lwd = 1),
       fontsize = list(text = 12, points = 10)
             )
trellis.par.set(prove.theme)
plot(ergoStool)

I also queried trellis.par.get by

names(trellis.par.get())

but still I'm not able to figure out which are the parameters, if any,
that control "pch" and "col" of the symbols.

Any help is highly appreciated.

Ottorino-Luca Pantani, Universit? di Firenze
Dip. Scienza del Suolo e Nutrizione della Pianta
P.zle Cascine 28 50144 Firenze Italia
Tel 39 055 3288 202 (348 lab) Fax 39 055 333 273 
OLPantani at unifi.it  http://www4.unifi.it/dssnp/