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    <p>I read answers and comments and I see that few things weren't mentioned:</p> <ol> <li><p><code>data.frame</code> uses <code>list(...)</code> version. Fragment of the code:</p> <pre><code>object &lt;- as.list(substitute(list(...)))[-1L] mrn &lt;- is.null(row.names) x &lt;- list(...) </code></pre> <p><code>object</code> is used to do some magic with column names, but <code>x</code> is used to create final <code>data.frame</code>.<br> For use of unevaluated <code>...</code> argument look at <code>write.csv</code> code where <code>match.call</code> is used.</p></li> <li><p>As you write in comment result in Dirk answer is not a list of lists. Is a list of length 4, which elements are <code>language</code> type. First object is a <code>symbol</code> - <code>list</code>, second is expression <code>1:10</code> and so on. That explain why <code>[-1L]</code> is needed: it removes expected <code>symbol</code> from provided arguments in <code>...</code> (cause it is always a list).<br> As Dirk states <code>substitute</code> returns "parse tree the unevaluated expression".<br> When you call <code>my_ellipsis_function(a=1:10,b=11:20,c=21:30)</code> then <code>...</code> "creates" a list of arguments: <code>list(a=1:10,b=11:20,c=21:30)</code> and <code>substitute</code> make it a list of four elements:</p> <pre><code>List of 4 $ : symbol list $ a: language 1:10 $ b: language 11:20 $ c: language 21:30 </code></pre> <p>First element doesn't have a name and this is <code>[[1]]</code> in Dirk answer. I achieve this results using:</p> <pre><code>my_ellipsis_function &lt;- function(...) { input_list &lt;- as.list(substitute(list(...))) str(input_list) NULL } my_ellipsis_function(a=1:10,b=11:20,c=21:30) </code></pre></li> <li><p>As above we can use <code>str</code> to check what objects are in a function.</p> <pre><code>my_ellipsis_function &lt;- function(...) { input_list &lt;- list(...) output_list &lt;- lapply(X=input_list, function(x) {str(x);summary(x)}) return(output_list) } my_ellipsis_function(a=1:10,b=11:20,c=21:30) int [1:10] 1 2 3 4 5 6 7 8 9 10 int [1:10] 11 12 13 14 15 16 17 18 19 20 int [1:10] 21 22 23 24 25 26 27 28 29 30 $a Min. 1st Qu. Median Mean 3rd Qu. Max. 1.00 3.25 5.50 5.50 7.75 10.00 $b Min. 1st Qu. Median Mean 3rd Qu. Max. 11.0 13.2 15.5 15.5 17.8 20.0 $c Min. 1st Qu. Median Mean 3rd Qu. Max. 21.0 23.2 25.5 25.5 27.8 30.0 </code></pre> <p>It's ok. Lets see <code>substitute</code> version:</p> <pre><code> my_ellipsis_function &lt;- function(...) { input_list &lt;- as.list(substitute(list(...))) output_list &lt;- lapply(X=input_list, function(x) {str(x);summary(x)}) return(output_list) } my_ellipsis_function(a=1:10,b=11:20,c=21:30) symbol list language 1:10 language 11:20 language 21:30 [[1]] Length Class Mode 1 name name $a Length Class Mode 3 call call $b Length Class Mode 3 call call $c Length Class Mode 3 call call </code></pre> <p>Isn't what we needed. You will need additional tricks to deal with these kind of objects (as in <code>write.csv</code>).</p></li> </ol> <p>If you want use <code>...</code> then you should use it as in Shane answer, by <code>list(...)</code>.</p>
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