The apparent axis or basal support of the scorpion's lung-books shown in the figures, is a false or secondary axis and merely a part of the infolded surface which forms the air-chamber.
The margins of the lamellae of the scorpion's lung-book, which are lowermost in the figures (fig.
221) Lankester described under the name " coxal glands " a pair of brilliantly white oviform bodies lying in the Scorpion's prosoma immediately above the coxae of the fifth and sixth pairs of legs (fig.
14.1130 indicates that there are 130 lamellae in the scorpion's lung-book, whilst 1150 indicates that 150 similar lamellae are counted in the gill of Limulus.
The scorpion's entosternite gives rise to outgrowths, besides the great posterior flaps, pf, which form the diaphragm, unrepresented in Limulus.
Rhabdom of a retinula of the scorpion's central eye, showing its five constituent rhabdomeres as rays of a star.
It is probably only sickly adults or young children of the human race who can be actually killed by a scorpion's sting.
By the crushing action of their pincers, and an alternate backward and forward movement, they bring the soft blood-holding tissues of the victim close to the minute pin-hole aperture which is the scorpion's mouth.
The muscles acting on the bulb-like pharynx now set up a pumping action (see Huxley, 26); and the juices - but no solid matter, excepting such as is reduced to powder - are sucked into the scorpion's alimentary canal.
Thelyphonus and its allies, however, have a long tactile caudal flagellum, the homologue of the scorpion's sting; but its exact use is unknown.