Footnotes:
[1] "World before the Deluge." Second edition.
[2] Examen Comparatif des Principales eaux Minérales Salines de France et d'Allemagne, par MM. L. Figuier et Mialhe. Read at the Académie de Médecin, 23rd of May, 1848.
[3] Sir J. Herschel's "Physical Geography," p. 22, gives the basis and details of this calculation.
[4] "La Terre et les Mers," p. 517. Troisième Ed.
[5] "Outlines of Comparative Anatomy."
[6] "Cours de Paleontologie Stratigraphique."
[7] "On en a vu vivre deux et même trois ans, sans recevoir de nourriture."—Vie des Animaux, p. 117.
[8] The term bivalve as constituting a class must be taken in a limited sense, for several genera, as pholas for example, have six or more valves.
[9] We give this illustration as representing the comparative size of the oysters at different ages; but it is necessary to state that the specimens were artificially attached to the block by means of glue for exhibition. Oysters always attach themselves by the back of the rounded shell near to the hinge, as stated at p. 363.
[10] The cause of the present scarcity of oysters is a much-vexed question. Mr. Frank Buckland, the greatest living authority on oyster and fish culture, attributes it to sudden changes of temperature at the critical period when the spat is newly formed, rather than to over-dredging.—Ed.
[11] The Brachiopoda may be thus tabulated:—
Family.
I. Lingulidæ, containing Lingula and other fossil genera.
II. Discinidæ, containing Siphonolreta and Discina.
III. Craniadæ, containing Crania.
IV. Productidæ, containing Chonetes and Productus, fossil.
V. Orthidæ, containing Calceola, Davidsonia, Strophomena, and Orthis.
VI. Rhynconellidæ, containing Atrypa, Pentamerus, and Rhynconella.
VII. Spiriferidæ, containing Uncites, Retzia, Athyris, and Spirifera.
VIII. Terebratulidæ, containing Thecidium, Agriope, Terebratella, and Terebratula.
[12] Woodward's Manual, p. 135.
[13] Is it necessary to say that even this account—apparently so well authenticated, not to speak of the representation drawn on the spot—should be taken "cum grano salis?"—Ed.
[14] The exceptions to these are the Doras, or flat-headed Hassar of India, which marches overland in large droves; the Swampines of Carolina (Hydrargyra); and the Perca Scandens, which in Tranquebar not merely walks over level ground, but climbs trees.
[15] Some fish, as the Chondropterygii, have no swimming bladder.—Ed.
[16] Dr. Fripp's theory of the properties of the fish's eye is very plausible.
1st. That the fish's eye in its normal state is arranged for the vision of near objects, and that the great refractive power of a prolate spheroid lens, such as exists in the fish, is adequate to the production of a picture at short focal distances, even with rays of light passing through so dense a medium as water.
2nd. That there is no accommodation of the fish's eye for extended limits of vision.
3rd. That the passive state of the fish's eye, being that in which it is enabled to see objects near and at moderate distance, no active or physiological change for accommodation of sight for distant objects takes place or seems necessary.
The dioptric arrangement, being the reverse of that which obtains in animals where "accommodation" is observed, and in whom the passive state is that of vision, arranged for distant objects, while the active state is that of vision accommodated at will for near objects.
4th. That the vascular distribution of the choroid vessels has no relation to any movement of the lens or change of its shape, but is arranged to meet the changes of static condition of the circulating fluid, and of dynamic force exerted by the heart under varying pressure from without; and that by such an arrangement, protection to the delicate tissues of the eye is afforded by a compensating balance between the tension of the blood within the vessels and the external pressure exerted upon them.
[17] "Lieutenant and Commander," by Captain Basil Hall. Bell & Daldy, London.
Transcriber notes:
[P.24.] 'he Equator.' changed to 'the Equator'.
[P.81.] 'Marseileise' changed to 'Marseillaise'.
[P.161.] Fig. 75. 'Dendrophylia' changed to 'Dendrophyllia'.
[P.186.] 'd'Acclimitation' changed to 'd'Acclimatation'.
[P.203.] Fig. 87. 'Hydra viridris' changed to 'Hydra viridis'.
[P.224.] 'vetebrated' changed to 'vertebrated'.
[P.299.] 'duvernea' changed to 'duvernæa', also in the list of illustrations.
[P.318.] 'coattings' changed to 'coatings'.
[P.335.] 'themeslves' changed to 'themselves'.
[P.352.] 'Malægrina' changed to 'Maleagrina'.
[P.403.] 'insensi le' changed to 'insensible'.
[P.408.] 'connnection' changed to 'connection'.
[P.426.] Plate XXIII. Fig. III. 'Vlouta' changed to 'Voluta'.
[P.523.] 'other other' changed to 'other'.
[P.531.] 'it own' changed to 'its own".
[P.580.] Added 'Plate' to illustration XXIX, 'Plate XXIX.'
[P.581.] 'cranes' changed to 'crans'.
Fixed various punctuation.