Beginners' zoology . and causesnaturalists to place them in a separate class, called batrachia(twice breather) or amphibia (double life). Tadpoles Suggestions. ---Tadpoles may be studied by placing a numberof frogs eggs in a jar of water, care being taken not to placea large number of eggs in a small amount of water. When theyhatch, water plants ( green algae) should be added for behaviour of frogs may be best studied in a tub of water. Atoad in captivity should be given a cool, moist place, and fed piece of meat placed near a toad may attract flies, and the toadmay be obse
Beginners' zoology . and causesnaturalists to place them in a separate class, called batrachia(twice breather) or amphibia (double life). Tadpoles Suggestions. ---Tadpoles may be studied by placing a numberof frogs eggs in a jar of water, care being taken not to placea large number of eggs in a small amount of water. When theyhatch, water plants ( green algae) should be added for behaviour of frogs may be best studied in a tub of water. Atoad in captivity should be given a cool, moist place, and fed piece of meat placed near a toad may attract flies, and the toadmay be observed while catching them, but the motion is so swiftas to be almost imperceptible. Live flies may be put into a glassjar with a toad. Toads do not move about until twilight, except 126 BATRACHIA 127 in cloudy, wet weather. They return to ponds and brooks inspring at the time for laying eggs. This time for both frogs andtoads is- shown by trilling. All frogs, except tree frogs, remain inor near the water all the Fig. 248. — Metamorphoses of the Frog, numbered in order. Do eggs hatch and tadpoles grow more rapidly in ajar of water kept in a warm place or in a cold place tIn pond water or in drinking water? Can the tadpoles beseen to move in the eggs before hatching } When dothe external gills show} (Fig. 248.) What parts may be described in a tadpole} What isthe shape of the Compare the tadpole with the fishas to (i) generalshape, (2) cover-ing, (3) fins, (4)tail, (5) gills. T~)r> tVif> PYtf^r Fig. 249. — Tadpole, from below, showing intestine , and internal gills. (Enlarged.) ^>ml gills disap-pear before or after any rudiments of limbs appear}(6, 7, Fig. 248.) Can you locate the gills after they be-come internal i (Fig. 249.)
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1921
