It shall be the duty of the county superintendent of public welfare to administer all of the funds of the county devoted to outdoor relief and allowances to needy mothers. He shall seek to discover any cases of neglect, dependent, defective or delinquent children in the county, and take all reasonable action in his power to secure for them the full benefit of the laws enacted for their benefit. Assistants to the county superintendents of public welfare shall perform such of the duties of the county superintendent of public welfare as he may assign to them.