SEA SICKNESS or without interruption, from remote geologi- cal epochs to the present time ; among these may be mentioned the Port Jackson shark (cea- traciori), and the gar pike (lepidosteus), which have come down to us without interruption, chimcera, percopi of Lake Superior, and soft- shelled tortoises (trionychidce), with more or less apparent disappearance. Several years ago it was suggested that the closest affinities of the sea serpent are with the marine lizards or enaliosaurians of the secondary age, and especially with the plesiosaurus. (See PLE- siosAURUS.) On the above principle it is main- tained that the enaliosaurians, found in the secondary, may have disappeared, actually or apparently, in the tertiary, to reappear at the present time. This is also the opinion of Agassiz, as given in the report of his lectures in Philadelphia in 1849, and reaffirmed in his "Geological Researches" (1871). Mr. Gosse has collected from various sources the argu- ments showing that the non-occurrence of dead animals is of little weight as disproving the existence of the sea serpent; its carcass would float only a short time, and the rock- bound coasts of Norway would be very un- likely to retain any fragment cast up by the waves ; many whales are known to natural- ists only from two or three specimens in as many centuries. The zeuglodon, a mamma- lian type of the tertiary epoch, coming near to the cetaceans and in some respects to the seals, may present some claim to be the sea serpent. (See ZEUGLODON.) The conclusion of the best naturalists is that the existence of the sea serpent is possibly a verity, and that it may prove to be some modified type of the secondary enaliosaurians, or possibly some form intermediate between them and the elongated cetaceans. See "Proceedings of the Boston Society of Natural History," vol. xvi. (March, 1874). SEA SICKNESS, an affection attended with nausea and vomiting, produced by the motion of a vessel at sea. Similar symptoms are also produced by swinging, waltzing, and riding backward in a coach ; but the greater and more regular oscillations of a ship have a stronger effect upon the nervous system. The susceptibility to this malady varies greatly ; some persons never experience nausea from this cause ; others may only suffer a few hours during a voyage of several days ; while still others are almost constantly sick while aboard ship, and fatal cases have been known. The premonitory symptoms are vertigo and some- times headache, and a peculiar feeling of "sink- ing" and distress at the pit of the stomach. Nausea soon appears, attended by distressing and convulsive vomiting and frequently diar- rhoea. It is more likely to attack those who are debilitated, or who have suffered nervous exhaustion or excitement consequent upon^ma- king preparations for the voyage, especially if there has been imprudence in taking food. Dr. Chapman, who wrote a pamphlet " On Sea SEASONS 741 Sickness, its Nature and Treatment " (London, 1864), is of opinion that " the motions of the vessel cause the accumulation of an undue amount of blood in the nervous centres along the back, and especially in those segments of the spinal cord related to the stomach and the muscles concerned in vomiting." The remedy which he asserts is the most scientific and efficacious is the application of ice bags to the spinal column, which act, according to his theory, as a sedative. They are made of thin caoutchouc, and are worn by the patient while walking about in ordinary apparel. Dr. For- dyce Barker, in a pamphlet on sea sickness, advises the observance of the following rules, which are principally preventive. In short pas- sages over rough water, those who are suscep- tible should make a hearty meal not more than two or three hours before going on board, and should keep as near as possible to the centre of the vessel, and lie down before she gets under way. The person should be well cov- ered and shielded as much as possible from disagreeable sights and smells. For ocean pas- sages similar care as to location should be ob- served in selecting berths. As a general rule of prevention, Dr. Barker advises regular and hearty eating in bed for one or two days, and during the voyage to take coffee or tea or some drink and food before" rising in the morn- ing. There is often a tendency to constipa- tion, which may be overcome by the use of laxatives. During an attack, especially if ac- companied by diarrhoea, medicines similar to those used in cholera morbus may be taken, as tincture of camphor, tincture of lavender combined with tincture of opium and tincture of capsicum, or a few drops of chloroform. Stimulating liniments may be applied to the pit of the stomach. If during the voyage the weather becomes rough, it is advisable to go to bed before getting sick. SEA SNIPE. See BELLOWS FISH, and PIPE Fisn. SEASONS (Fr. saisons), the quarters of the year, spring, summer, autumn, and winter. These periods are determined astronomically by the apparent movements of the sun (the real movements of the earth) in the ecliptic. The passage of the sun across the equator, bring- ing on days of greater length than the nights, marks the vernal or spring equinox, and oc- curs about March 21 for the northern hemi- sphere and Sept. 23 for the southern. These dates also mark the autumnal equinox or com- mencement of the autumn, the hemispheres being reversed. The summer solstice, when the day is of greatest length and the astro- nomical summer begins in the northern hemi- sphere, is about June 21, and the winter sol- stice about Dec. 21. In the figure, S repre- sents the position of the sun, A the position of the earth at the vernal equinox in the northern hemisphere (about March 21), and N the north pole. Both poles just catch the light of the sun, and in all other parts of the
