INSTITUTO OSWALDO CBUZ 
CAIXA POSTAL 926 
BRASIL 
9 
RIO DE JANEIRO 
ve 
awav or destroy the frog so that the "ghost" is successfully laid 
The frog chorus is heard only in the mating season, which 
in Brazil lasts for most of the summer, iha males i.iahe,^ the call to 
summon the females to the shahlow pool vhere mating takes place, ihe 
ei?p's often nuxheririg several hundreds from a single female at one 
laying, are deposited in the water, by many species of frogs. The 
tiiin gelatinous coatirig coveriiig each egg begins to absorb water as 
soon as it is laid, and soon riiai:es a cushion jelly-like cover for 
the tiny black embryo developing inside, in three or ^ four days ^ the 
egg has grown and elongated into a tiny foi’m resembling an Indian 
club in shape. Movement now talies place within c-he egg, the ttiin 
jelly-like tissue is broken, and the newborn ta.dpole awkwardly la.shevS 
its 'way to the surface, being at the raouient without gills or tail, 
and hangs there Vaith the small heaa end uppermost, and the heay^' 
body still containing most of the yolk-nourishment ha.ngin.g down. At 
this stage the tadpoles look like tiny black beads floatiijg in the 
Y/ater. By the next dap gi^ls have sprouted irom the sio.e of the xiecx 
and a flat rudderlike tail has begun to make its appearance, and 
from rioYi on the power of locomotion is gmatly increased, so that 
p'oung tadpoles become ver^r difficult to catcji. The gills allow^ tne 
absorbtion of oxygen from th.e v/ater in about the same manner that 
a fish breathes. The mouth of the tadpole is^at this stage equipped 
with 0. diminutive horny black beak, al-most like that of a parrot, 
YYith which it scapes off the green scum of algae and other microscop- " 
ic plants for food, or nibbles tiny scrapes of dead animal tissue 
that may come its wey''. Its body rapidly grows and elongatss^and be— ^ 
comes characteristic of its species in color, shape and mouth struct- 
ure. in a few days the gills are reabsorbed and disappear, and the 
tadTYole now foreshadows its coming terrestrial life by the develop- 
ment of two nostrils on top of its head, and must rusm to uhe surj.aco 
everv fev/ minutes to get a lungful of air, oome tadpoles of particulai 
species attain a rather large size, aliiiost as big as a. hen's egg 
in fact, and are often very sluggish, lying all day in the shallows 
in the gray mud which almost x->eif®ctly conce^s them, or moving ^ouu 
like ai^essly animate guiadrorjs, in search of some tiding to eat, inis 
■oassive existence lasts for some weeks, at ten f oi‘ ^ mon'tha , and tlieii^^ 
a nevv jikase aiopears with the development of the hind legSj which tirst 
shOY^ as tiny brad-like structures a.t tlie Sj.des ot the tail, puu p/nich 
soon groYY into a good resemblance of the legs ot the aQult.tne fore— 
arpis anoean next, and the head also has under*goiiQ cha.nges in contour, 
the nose becoming riioi’e pointed, the beak disapxoearing, a true frcg- 
rnuth taking- its place, and a flat eardrum developing on the side ot 
the head. Mow 'the tail shortens and diminishes and is finally complete- 
ly absorbed into the body tissue, and Yve have a "tiny teir2Si.rj.3J.^ti 
tha.t leaves the u'ater completely cuid hops about in the muo. lookixig 
for food in the shape of insects that he can captui'-e and devour* 
Tf our friend the frog is fortunate enough to ^escape being eaten up 
bv his older brothers or by the numerous enemies which are alYvays 
on the watch, he will continue to grow and thrive during the winuer 
season, and by the followine' spring will take nis_pla_ce_ as a tieiaber 
of fliG chorus which 1 spoke ah out at. txie oeginriin^ ox r/iy 
typ. do instituto Osvvaldo Cnrt 
