The Cambridge natural history, Vol. 08 (of 10)Gadow, Hans
Science
The Cambridge natural history, Vol. 08 (of 10)
Gadow, Hans
Animals
The eggs are enclosed in batches in leaves near the margin of the water.
Budgett has been able to watch the whole process of oviposition and
fertilisation. He found, at 11 P.M., a female carrying a male upon her
back, wandering about in search of a suitable leaf. At last the female,
climbing up the stem of a plant near the water's edge, reached out and
caught hold of the {205}tip of an overhanging leaf, and climbed into it.
Both male and female held the edges of the leaf together, near the tip,
with their hind-legs, while the female poured her eggs into the funnel thus
formed, the male fertilising them as they passed. The jelly in which the
eggs were laid was of sufficient firmness to hold the edges of the leaf
together. Then moving up a little further, more eggs were laid in the same
manner, the edges of the leaf being fastened together by the hind-legs, and
so on up the leaf until it was full. As a rule, two briar-leaves were
filled in this way, each containing about 100 eggs. The time occupied in
filling one leaf was three-quarters of an hour.
Development proceeds rapidly. Within six days the embryo increases from the
2 mm. of the egg-diameter to 9 or 10 mm. When it leaves the leaf it is a
transparent glass-like tadpole, whose only conspicuous parts are the eyes.
These are very large and of a bright metallic green colour, so that when
swimming in the water all that is seen is a pair of jewel-like eyes. The
newly-hatched tadpole has also a bright metallic spot between the nostrils
somewhat in front of the pineal spot. This is the point which touches the
surface of the water when the tadpole is in its favourite position. Whether
it is a protective coloration, or some mechanical arrangement for holding
the surface, Budgett could not make out.
The egg contains a great amount of yolk; the rest of the jelly-like
contents of the egg becomes fluid, so that towards the end of embryonic
life the larva comes to lie quite freely within a membranous capsule. The
external gills appear on the third day, and reach their greatest size on
the fifth, when these bright red filamentous organs extend beyond the vent.
By the time the tadpoles are ready to be hatched these gills have quite
disappeared, there is a median spiracle, and the lungs are shining through
the transparent body-wall. Five weeks later, _i.e._ six weeks after the
eggs were laid, the tadpole is 8 cm. long, glossy green above, rosy and
silvery below, and the hind-limbs protrude. The young frog at the close of
its metamorphosis is two-thirds the length of the adult, and at this time
acquires the red flanks barred with black.
The first account of the breeding of _Phyllomedusa_ was given by v.
Ihering[90] concerning _Ph. iheringi_ of Southern Brazil.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account