6. Introduce the inoculum by means of a hypodermic syringe, perforating the dura mater with the needle and depositing the material immediately below this membrane, at the same time taking care to avoid injuring the sinuses. 7. Turn back the flap of skin and secure it in position with Michel's steel clips. 8. Dress with sterile gauze and wool and seal the dressing with collodion. 9. Label, etc. (b) _Intracerebral._--This inoculation is performed precisely as for subdural save in step 6 the needle after perforating the dura mater is pushed onward into the substance of one or other cerebral hemispheres before the contents are ejected. [Illustration: FIG. 188.--Intracranial inoculation of rabbit. The circle indicates the situation of the trephine hole.] ~6. Intraocular.~-- (a) _Fluid Inoculum._--(_Anæsthetic, cocaine._) 1. Instil a few drops of a sterile solution of cocaine, and repeat the instillation in two minutes. 2. Five minutes later have the animal firmly held by an assistant as in intravenous injection (see Fig. 189), the head being steadied by the assistant's hands. 3. Select two needles to accurately fit the same syringe and sterilise. 4. Attach one needle to the syringe and take up the required dose of inoculum and remove the needle. 5. Steady the eye with fixation forceps; then pierce the cornea with the other syringe needle and allow the aqueous to escape through the needle. 6. Without removing the needle from the cornea attach the syringe and make the injection into the anterior chamber. 7. Irrigate the conjunctival sac with sterile saline solution. 8. Label, etc. (b) _Solid Inoculum._--(_Anæsthetic, A. C. E._) 1. Anæsthetise the animal and secure it firmly to the operating table. 2. Irrigate the conjunctival sac thoroughly with sterile saline solution. 3. Make an incision through the upper quadrant of the cornea into the anterior chamber by means of a triangular keratome. 4. Separate the lips of the corneal wound with a flexible silver spatula; seize the solid inoculum in a pair of iris forceps, introduce it through the corneal wound, and deposit it on the anterior surface of the iris; withdraw the forceps. 5. Again irrigate the sac and the surface of the cornea. 6. Release the animal from the operating table. 7. Label, etc. ~7. Intrapulmonary.~-- _Fluid Inoculum._--(_Anæsthetic, none._) 1. Have the animal firmly held by an assistant. (In this case the foreleg of the selected side is drawn up by the assistant and held with the ear of that side.) 2. Shave carefully in the axillary line and disinfect the denuded skin. 3. Thrust the needle of the syringe boldly through the fifth or sixth intercostal space into the lung tissue. 4. Inject the contents of the syringe slowly. 5. Label, etc. ~8. Intravenous.~-- _Fluid Inoculum._--(_Anæsthetic, none._)