ERROR IN VIEW (TREE) Odoo 11

It does not show me in the tree view the fields last name, security num. Just the name. I add models and views:

 class centromedico_pacientes(models.Model): #rw by secretaria users, r doctores/enfermeros
_name = 'centromedico.pacientes'

name = fields.Char(string="Nombre", required=True)
apellidos = fields.Char(string="Apellidos", required=True)
numserguridad = fields.Integer(string="Número seguridad social", required=True)
cita = fields.One2many("centromedico.citas","cpaciente",string="Libros")

class centromedico_citas (models.Model): #rw by secretaria users, r doctors _name = 'centroomedico.citas'

 fconsulta = fields.Datetime(string="Fecha consulta", required=True)
cpaciente = fields.Many2one('centromedico.pacientes', string="Paciente")

And this would be the view for the centromedico_citas model, which is where the tree does not show me well:

 <record model="ir.ui.view" id="centromedico.citas_tree"> 
  <field name="name">centromedico.citas.tree</field>
  <field name="model">centromedico.citas</field> 
  <field name="arch" type="xml">
    <tree>
      <field name="fconsulta"/>
      <field name="cpaciente">
        <field name="name"/>
        <field name="apellidos"/>
      </field>
    </tree>
  </field>
</record>

<record model="ir.ui.view" id="centromedico.citas_form">
  <field name="name">centromedico.citas.form</field>
  <field name="model">centromedico.citas</field> 
  <field name="arch" type="xml">
    <form>
      <group> 
        <field name="fconsulta"/>
        <field name="cpaciente">
          <tree>
            <field name="name"/>
            <field name="apellidos"/>
            <field name="numserguridad"/>
          </tree>
        </field>
      </group>
    </form>
  </field>
</record>