On the first issue of a certificate of title the seal of the office of titles shall be impressed on the certificate together with the signature of the Registrar; and on the entry thereon of every subsequent memorial, that memorial shall be signed by the Registrar and it shall not be necessary to impress the seal on it; and such certificate and memorial shall be received in all courts as conclusive evidence that the instrument has been registered; and all courts and persons acting judicially shall take judicial notice of the seal and signature and shall presume that the seal was properly impressed and that the signature was properly attached.