It was shown in a previous report1 that in experimental poliomyelitis one or both of the olfactory bulbs exhibited characteristic pathologic changes, that is, neuronal necrosis, neuronophagia and perivascular and meningeal cellular infiltration, when the virus invaded the nervous system by the olfactory pathway but not after invasion by other pathways (subcutaneous, intrasciatic, intraocular, tonsillopharyngeal and intracerebral). Despite the fact that in recent years there has been a strong tendency to regard the olfactory pathway as the usual portal of entry for the virus in man, there is actually no direct evidence for such an assumption. It was, therefore, desirable to determine whether or not the olfactory bulbs in human poliomyelitis showed changes similar to those found in experimental poliomyelitis which was induced by nasal instillation of the virus.
Smith's2 report, in 1934, on 56 olfactory bulbs from about 40 cases was inconclusive, partly because the statement that