Prince Rupert's Drops are drops of glass thrown while in a state of fusion into water, and thus suddenly consolidated, taking generally a form somewhat like a tadpole. The thick end may be struck with a hammer without breaking, but should the smallest part of the tail be nipped off, or the surface scratched with a diamond, the whole flies into fine dust with an almost explosive force. This phenomena is due to the state of strain in the interior of the mass of glass, caused by the sudden consolidation of the crust which is formed while the internal mass is still liquid. This tends to contract on cooling, but is prevented by the molecular forces which attach it to the crust. This philosophical toy gets its name from being invented or being brought first into notice by Prince Rupert, nephew of Charles I. Research Prince Rupert's Drops
Amphibia (the amphibians) is a class of vertebrate animals, which in their early life breathe by gills or branchiae, and afterwards partly or entirely by lungs. The Frog, breathing in its tadpole state by gills and afterwards throwing off these organs and breathing entirely by lungs in its adult state, is an example of the latter phase of amphibian existence. The Proteus of the underground caves of Central Europe exemplifies forms in which the gills of early life are retained throughout life, and in which lungs are developed in addition to the gills. A second character of this group consists in the presence of two occipital condyles, or processes by means of which the skull articulates with the spine or vertebral column; Reptiles possessing one condyle only. The class is divided into four orders: the Ophiomorpha (or serpentiform), represented by the Blind-worms, in which limbs are wanting and the body is snake-like ; the Urodela or Tailed Amphibians, including the Newts, Proteus, Siren, etc; theAnoura, or Tailless Amphibia, represented by the Frogs and Toads; and the Labyrinthodontia, which includes the extinct forms known as Labyrinthodons. Research Amphibia
Amphiuma is a genus of amphibians which frequent the lakes and stagnant waters of North America. The adults retain the clefts at which the gills of the tadpole projected. Research Amphiuma
Ascidia (named from the Greek, askos, a wine-skin) is a name given to the Sea-squirts or main section of the Tunicata, a class of animals of low grade, resembling a double-necked bottle, of a leathery or gristly nature, found at low-water mark on the sea-beach, and dredged from deep water attached to stones, shells, and fixed objects. One of the prominent openings admits the food and the water required in respiration, the other is the excretory aperture. A single ganglion represents the nervous system, placed between the two apertures. Male and female reproductive organs exist in each ascidian. They pass through peculiar phases of development, the young ascidian appearing like a tadpole-body. They may be single or simple, social or compound. In social ascidians the peduncles of a number of individuals are united into a common tubular stem, with a partial common circulation of blood. In these animals early evolutionists saw a link between the Mollusca and the Vertebrata. Research Ascidia
Frog is the common English name of a number of animals belonging to the class Amphibia, having four legs with four toes on the fore feet and five on the hind, more or less webbed, a naked body, no ribs, and no tail. Owing to the last peculiarity frogs belong to the order of amphibians known as Anura or tailless Amphibia. The tongue is fleshy, and is attached in front to the jaw, but is free behind, so that the hinder extremity of the tongue can be protruded.
Frogs are remarkable for the transformations they undergo before arriving at maturity. In the spring the spawn is deposited in ponds and other stagnant waters in large masses of gelatinous matter. These masses, with black globules scattered through them, soon manifest change, and after a time the young escapes as a tadpole, as an animal with short body, circular suctorial mouth, and long tail, compressed from side to side. Gillsproject on either side of the head from a cleft which answers in position to the gill opening of fishes. The hind limbs first appear as buds, later the fore limbs project, the gills disappear, the lungs becoming more fully developed; the tail gradually shrinks and disappears, and the animal, which was at first fish-like, then closely resembled a newt (or tailed Amphibian), finally assumes the adult or tailless form.
The mature frog breathes by lungs, and cannot exist in water without coming to the surface for air. The only British species is the common frog (Rana temporaria), but the tribe is very numerous, other varieties being the edible frog (Rana esculenta) of the south of Europe, eaten in France and South Germany, the hind quarters being the part chiefly used; the bull-frog of America (Rana pipiens), 8 to 12 inches long, so named from its voice resembling the lowing of a bull; the blacksmith frog of Janeiro; the Argus frog of America, etc. Of the tree-frogs most belong to the genus Hyla. Frogs swim with rapidity, and move by long bounds, being able from the power of the muscles of their hind-legs to leap many times their own length. Research Frog
Pipa is a genus of aquatic tongueless toad of the order Aglossa. The head is depressed and triangular in shape; the skin is covered with small tubercles; the digits on the fore limb are slender, and free from one another, and furnished with star-shaped processes at the tip, while those on the hind limbs are broadly webbed. The genus is peculiar for the habit which the female possesses of carrying the eggs until they hatch in little pockets in the skin of her back. As the eggs are laid they are spread out over the back, the male assisting the process; each egg then sinks into a pouch of the epidermis, which is subsequently closed by a lid. From these skin pockets emerge the young after about three months, and then resemble the parents except in size, the gilled tadpole stage being omitted from the life history. Research Pipa
Toad (Bufo) is a large genus of over 100 species of batrachians, of world-wide distribution, with the exception of Australia and Madagascar ; most abundant in tropical America and the Indo-Malayan region. Closely related to the frogs (Rana), they differ from them in their flatter upper side, broader head, shorter limbs, and in the skin being dry and pimply, with glands which secrete an acrid fluid. In addition, the toads are toothless, and the tip of the tongue is not divided. They pass through a larval ('tadpole') stage similar to that of the frog, but the eggs, which vary from 700 to 2,000, are extruded in a double chain enclosed in a string of jelly, which is wound around water plants. The tadpoles are smaller and darker than those of the frog. The genus is represented in Britain by two species: the common toad (Bufo vulgaris) and the natterjack (Bufo calamita); but the former does not occur in Ireland.
The common species has on its upper side some tint of brown or grey, varying with its surroundings; and the under parts are whitish, more or less spotted with black. It seeks drier situations than the frog, and is inactive during the day, coming abroad in the dusk and feeding upon insects, worms, and snails large individuals on occasion catching small mice. One toad will in a night's foraging consume vast numbers of insects, so that its cooperation is always to be encouraged by gardeners. From ancient days the toad has been the subject of numerous erroneous beliefs, e.g. the possession of a jewel in its head, the power of ejecting venom, and of living for centuries entombed in solid stone or the heart of a tree. The toad hibernates, retiring in autumn to holes in dry ground or other suitable retreats, and on awakening in spring immediately seeks the ponds or ditches for mating and egg-laying. Research Toad
Abbreviations
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