t the
condition may follow on infections with ordinary pyogenic cocci,
pneumococci, the influenza bacillus or the bacillus coli.

In addition to the use of anti-syphilitic remedies, or of sera
directed to neutralise the toxins of the causative organism, attention
must be directed to the bladder, and steps taken to prevent cystitis
and the formation of bed-sores.

CONGENITAL DEFORMITIES OF THE SPINE

#Spina Bifida.#--Spina bifida is a congenital defect in certain of the
vertebral arches, which permits of a protrusion of the contents of the
vertebral canal. It is due to an arrest of development, whereby the
closure of the primary medullary groove and the ingrowth of the
mesoblast to form the spines and laminae fail to take place. The cleft
may implicate only the spinous processes, but as a rule the laminae
also are deficient. The defect usually extends over several vertebrae
(Fig. 219). While the protrusion varies much in size, there is no
constant ratio between the dimensions of the swelling and the extent
of the defect in the neural arches.

[Illustration: FIG. 219.--Meningo-myelocele of Thoracico-lumbar
Region.]

The condition is comparatively common, being met with in about one out
of every thousand births. It is most frequent in the lumbar and sacral
regions (Fig. 219), but occurs also in the cervical (Fig. 220) and
thoracic regions. It is not uncommon to find spina bifida associated
with other congenital deformities such as hydrocephalus, club-foot,
and extroversion of the bladder.

[Illustration: FIG. 220.--Meningo-myelocele of Cervical Spine.]

_Varieties._--Four varieties are usually described according to the
character of the protrusion. They are analogous, to a certain extent,
to the varieties of cephalocele (p. 387). (1) _Spinal meningocele_, in
which only the membranes, filled with cerebro-spinal fluid, are
protruded. (2) _Meningo-myelocele_, the form most commonly met with
clinically, in which the cord and some of the spinal nerves are
protruded, and spread out over the inner aspect of the sac (Figs. 219,
220). (3) _Syringo-myelocele_, in which there is a dilatation of the
central canal in the protruded part of the cord. In these three forms
the protrusion may be covered by healthy skin, or by a thin, smooth,
translucent membrane through which the contents are visible.
Frequently this thin covering sloughs or ulcerates, and permits the
cerebro-spinal fluid to drain away. (4) In the _myelocele_, th