Exhibit 3.64

Microfilm Number 200094-193	Filed with the Department of State on 12-18-00
Entity Number 2978352	XXXXXX
	Secretary of the Commonwealth

CERTIFICATE OF LIMITED PARTNERSHIP
DSCB:15-8511 (Rev 90)

In compliance with the requirements of 15 Pa.C.S. § 8511 (relating to certificate of limited partnership), the undersigned, desiring to form a limited partnership, hereby certifies that:

1. The name of the limited partnership is: e-Tenants.com Holding, L. P.

2. The (a) address of this limited partnership’s initial registered office in this Commonwealth or (b) name of its commercial registered office provider and the county of venue is:

(a) 14 Campus Boulevard, Suite 100         Newtown Square          PA          19073          Delaware

Number and Street                                           City                     State           Zip             County

(b) c/o:

Name of Commercial Registered Office Provider                                         County     

For a limited partnership represented by a commercial registered office provider, the county in (b) shall be deemed the county in which the limited partnership is located for venue and official publication purposes.

3. The name and business address of each general partner of the partnership is:

               Name                                                       Address          

Brandywine Operating Partnership, L. P.,       14 Campus Boulevard, Suite 100, Newtown Square, PA 19073

4. (Check, and if appropriate complete, one of the following):

The formation of the limited partnership shall be effective upon filing this Certificate of Limited Partnership in the Department of State.

The formation of the limited partnership shall be effective on:                  at                      

	Date                  Hour
5.	The specified effective date, if any is:                                                                            N/A

month                  day                year                 hour, if any

IN TESTIMONY WHEREOF, the undersigned general partner(s) of the limited partnership has (have) executed this Certificate of Limited Partnership this      6th      day/of       December       , 2000.

Brandywine Operating Partnership, L. P., general partner
By:  Brandywine Realty Trust, general partner of
        Brandywine Operating, Partnership, L. P.

By	/s/ Gerard H. Sweeney
	Gerard H. Sweeney, Sr. President & CEO	(Signature)

PENNSYLVANIA DEPARTMENT OF STATE CORPORATION BUREAU
Certificate of Amendment-Domestic (15 Pa C.S.)
Entity Number
			Limited Partnership (§ 8512)
			Limited Liability Company (§ 8951)
Name	PEPPER HAMILTON LLP			Document will be returned to the name and address you enter to the left.
Address	200 ONE KEYSTONE PLAZA NORTH FRONT AND MARKET STREETS P.O. BOX 1187
	City	State	Zip Code
	HARRISBURG,	PA	17108-1181

Fee: $52	Filed in the Department of State on Jun 06 2002
	XXXXXX
	ACTING Secretary of the Commonwealth

In compliance with the requirements of the applicable provisions (relating to certificate of amendment), the undersigned, desiring to amend its Certificate of Limited Partnership Organization, hereby certifies that:

1. The name of the limited partnership limited liability company is:
“UNREADABLE TEXT”

2. The date of filing of the original Certificate of Limited Partnership Organization:
“UNREADABLE TEXT”

3. Check and if appropriate complete one of the following:

	The amendment adopted by the limited partnership/limited liability company, set forth in full, is as follows:
	The amendment adopted by the limited partnership/limited liability company is set forth in full in Exhibit A attached hereto and made a part hereof.

4. Check and if appropriate complete one of the following:

The amendment shall be effective upon filing this Certificate of Amendment in the Department of State.

	The amendment shall be effective on _______ at ______
	Date            Hour

5. Check if the amendment restates the Certificate of Limited Partnership/Organization:

The restated Certificate of Limited Partnership/Organization supersedes the original Certificate of Limited Partnership/Organization and all previous amendments thereto.

IN TESTIMONY WHEREOF, the undersigned limited partnership/limited liability company has caused this Certificate of Amendment to be executed this

4th day of June, 2002.



e-Tenants.com Holding, L.P.

Name of Limited Partnership/Limited Liability Company

XXXXXX

Signature

(See Exhibit B attached)

Title

EXHIBIT A

TO CERTIFICATE OF AMENDMENT

e-TENANTS.COM HOLDING, L. P.

Article 4 of the Certificate of Limited Partnership shall be amended, so that, as amended, Article 4 shall read as follows:

“Article 4. The address of this limited partnership’s registered office in this Commonwealth is: 401 Plymouth Road, Suite 500, Plymouth Meeting, PA 19462, Montgomery County.”

Article 6 of the Certificate of Limited Partnership shall be amended, so that, as amended, Article 6 shall read as follows:

“Article 6. The name and business address of each general partner is: Brandywine Operating Partnership, L.P., 401 Plymouth Road, Suite 500, Plymouth Meeting, PA 19462, Montgomery County.”

Article 7 of the Certificate of Limited Partnership shall be amended, so that, as amended, Article 7 shall read as follows:

“Article 7. The address of the office at which is kept a list of the names and addresses of the limited partners and their capital contributions is: 401 Plymouth Road, Suite 500, Plymouth Meeting, PA 19462, Montgomery County.”

EXHIBIT B

to

CERTIFICATE OF AMENDMENT

e-TENANTS.COM HOLDING, L. P.

By:	Brandywine Operating Partnership, L.P., a Delaware limited partnership General Partner
By:	Brandywine Realty Trust, a Maryland real estate trust
By:	/s/ Brad A. Molotsky
	Brad A. Molotsky, Secretary