list concatenation

Dear R gurus,


first let me apologize for a question that might hve been answered
before. I was not able to find the solution yet. I want to concatenate
two lists of lists at their lowest level.

Suppose I have two lists of lists:

list.1 <- list("I"=list("A"=c("a", "b", "c"), "B"=c("d", "e", "f")),

              "II"=list("A"=c("g", "h", "i"), "B"=c("j", "k", "l")))


list.2 <- list("I"=list("A"=c("A", "B", "C"), "B"=c("D", "E", "F")),

              "II"=list("A"=c("G", "H", "I"), "B"=c("J", "K", "L")))

list.1

$I
$I$A
[1] "a" "b" "c"

$I$B
[1] "d" "e" "f"


$II
$II$A
[1] "g" "h" "i"

$II$B
[1] "j" "k" "l"

list.2

$I
$I$A
[1] "A" "B" "C"

$I$B
[1] "D" "E" "F"


$II
$II$A
[1] "G" "H" "I"

$II$B
[1] "J" "K" "L"


Now I want to concatenate list elements of the lowest levels, so the
result looks like this:


$I
$I$A
[1] "a" "b" "c" "A" "B" "C"

$I$B
[1] "d" "e" "f" "D" "E" "F"


$II
$II$A
[1] "g" "h" "i" "G" "H" "I"

$II$B
[1] "j" "k" "l" "J" "K" "L"


Has anybody a good solution for that?

mapply( function(x,y) mapply(c, x, y, SIMPLIFY=FALSE),

Best,

Georg