The classification into epithelial organs, connective tissues, and the more specialized muscle and nerve, was largely due to him; and he proved the presence of neuroglia in the brain and spinal cord, discovered crystalline haematoidine, and made out the structure of the umbilical cord.
The activity of the spinal cord is similarly depressed.
The substance of the brain, spinal cord and nervetrunks is normal, but the membranes are engorged.
If, for example, the brain and spinal cord removed from an animal be bruised and brought into contact with tetanus toxin, a certain amount of the toxicity disappears, as shown by injecting the mixture into another animal.
It excites the motor areas of the spinal cord and increases their reflex irritability.