CHAPTER XI

THE EVIDENCE OF THE AUDITORY APPARATUS AND THE ORGANS OF THE LATERAL LINE

Lateral line organs--Function of this group of organs--Poriferous sense-organs on the appendages in Limulus--Branchial sense-organs-- Prosomatic sense-organs--Flabellum--Its structure and position-- Sense-organs of mandibles--Auditory organs of insects and arachnids-- Poriferous chordotonal organs--Balancers of Diptera--Resemblance to organs of flabellum--Racquet-organs of Galeodes--Pectens of scorpions--Large size of nerve to all these special sense-organs-- Origin of parachordals and auditory capsule--Reason why VIIth nerve passes in and out of capsule--Evidence of Ammocoetes--Intrusion of glandular mass round brain into auditory capsule--Intrusion of generative and hepatic mass round brain into base of flabellum-- Summary 355