Cases showing absence of the olfactory lobe are rare. In 1914 Weidenreich1 reported one case and quoted nine others from the literature on this subject. Kundrat,2 in his monograph, "Arhinencephalie," describes brains which have no olfactory lobe, but are combined with other brain anomalies. Besides these two reports I was able to find one case reported by Valenti.3 But according to Weidenreich all reports which he quoted lack detailed information, especially in that they do not discuss the area of the brain supposedly connected with the olfactory nerve and therefore called "rhinencephalon." Valenti's report contains no statement about this area.
In Weidenreich's case there was entire absence of the bulbus and tractus olfactorius in both hemispheres. We assume that the rhinencephalon governs the sense of smell as found by Broca and Zuckerkandl in their studies in comparative anatomy, and by Retzius embryologically. If this is true also
FUMIO TANAKA. ABSENCE OF LOBUS OLFACTORIUS AND SCLEROSIS OF CORNU AMMONIS. Arch NeurPsych. 1920;4(2):151–170. doi:10.1001/archneurpsyc.1920.02180200016003