from SC 13G/A
1 page
<page> Exhibit 1 Agreement Pursuant to Rule 13d-1(f) Promulgated Pursuant to the Securities Exchange Act of 1934, as Amended, the Undersigned Agree That the Attached Schedule 13g Is Being Filed on Behalf of Each of the Undersigned. February 13, 1998 Venrock Associates By: /S/ Ted H. McCourtney Ted H. McCourtney General Partner February 13, 1998 Venrock Associates II, L.P. By: /S/ Ted H. McCourtney Ted H. McCourtney General Partner February 13, 1998 General Partners /S/Mark W. Bailey Mark W. Bailey /S/ Anthony B. Evnin Anthony B. Evnin /S/ David R. Hathaway David R. Hathaway /S/ Patrick F. Latterell Patrick F. Latterell /S/ Ted H. McCourtney Ted H. McCourtney /S/ Ray A. Rothrock Ray A. Rothrock /S/ Kimberley A. Rummelsburg Kimberley A. Rummelsburg /S/ Anthony Sun Anthony Sun
