That is not the case for Solaris and other Unix systems. You need to get a little more creative there. Basically you will need to use an intermediate command to quote the resulting lines from find so xargs can parse them correctly.
As an example in Solaris you would find an occurrence of a pattern string inside all files starting at a given directory (in case blanks are expected in names) as shown below:
$ find /path/to/dir/ -name "*" | sed 's/.*/"&"/' | xargs grep "searchedPattern"