Source Record ID not accepted in API Activity Get

1. Log into the demo site
2. Go to the api explorer
3. Select "Activity" and "Get"
4. In the parameters, enter source_record_id=202
5. Observe that the values returned are :
"is_error":0,
"undefined_fields":["source_record_id"],
"version":3,
"count":0,
"values":[]
6. Yet if you enter source_contact_id=202 it returns:
"is_error":0,
"undefined_fields":["source_contact_id"],
"version":3,
"count":25,
"values":[{
"id":"1",
7. Also observe that in the 4.4.4 mysql DB structure there is source_record_id under the activity type