Condensed Consolidated
       Balance Sheet Data:                    March 31,        December 31,
                                                 2002             2001
                                              (unaudited)
     Assets
       Cash, cash equivalents
         and short-term investments          $215,152,890     $226,924,293
       Other current assets                     8,879,714        6,384,531
       Land, property and
         equipment, net                        25,894,338       23,268,567
       Acquired technology,
         investments and other assets          20,463,895       20,396,319
          Total assets                       $270,390,837     $276,973,710

     Liabilities and Stockholders' Equity
       Liabilities                             $7,009,840       $7,500,032
       Stockholders' equity                   263,380,997      269,473,678
          Total liabilities and
           stockholders' equity              $270,390,837     $276,973,710