Marvels of the Universe 



599 



nature, being perhaps developed from a portion of the 

 shell-membrane. 



In these cells the young toads undergo their full 

 development, not emerging untU they are miniature 

 repKcas of their parents. As a rule, from sixty to 

 seventy offspring are developed in the back of each 

 female, but in some instances the number may be 

 increased to so many as one hundred and twenty ; 

 the whole process of development occupying eighty- 

 two days. \ATien ready to emerge the young toads 

 do not appear to require anj^ assistance, each pushing 

 off the hd of its cell by thrusting forth its head or 

 a leg, and then proceeding to climb out. After the 

 young have come forth, the outer layer of the skin 

 of the back of the female dries up and is shed, while 

 the hone5-comb-hke cells gradually close up, the posi- 

 tion of each being indicated by a small, pimple-like 

 elevation. 



Strange as is this mode of nurturing and developing the eggs, it is not absolutely un- 

 paralleled, for there exists in the island of Ceylon a species of frog belonging to the same 

 group as the so-called Fljdng Frog of Java, in which the eggs, to the number of about a 

 score, become attached to the skin of the under surface of the body of the female, on which, 

 after hatching, they leave small, shallow pits. In this case, however, it does not yet appear 

 to be known what becomes of the tadpoles, although it is believed that they do not undergo 

 development in the parental skin. Neither is it ascertained by what means the eggs are implanted 

 in the skin. 



It may be added that those large and handsome brown Mauritian cowry shells in which the 

 upper surface is marked by a number of yellowish spots are frequently called Surinam- 

 Toad cowries, on account of a fancied resemblance to the back of a nursing female of the 

 species forming the subject of the present article. 



Pholo ii/] 



[//. ,S. Cheacin. 



A PARASITE OF THE PARTRIDGE. 



Notice the method of attachment of the eggs 

 to the feather. 



BIRD PARASITES 



BY JOHN' J. \V.\RD, F.E.S. 



FoRTUX.ATELY, Science has no blushes ; otherwise, I 

 might apologize to my readers for introducing this 

 somewhat indelicate subject. All living animals, great 

 or small, are pestered more or less by other animals 

 specially adapted to prey upon them ; it is possible 

 that there are no exceptions to the rule. 



Even the slug, whose viscid secretions might be 

 regarded as an effective barrier to all such trespassers, 

 has its own special parasite, which plunges through 

 the exudations of its host with perfect freedom ; 

 while the frog proceeds upon his watery way accom- 

 panied by at least twenty kinds of these uninvited 

 visitors. The bullet-proof hide of the rhinoceros and 

 the leathery skin of the hippopotamus are subject to 

 the attentions of the torturing inflictions of a tick. 



Photo 6y] [//. .V. Cheavin. 



A PARASITE OF THE THRUSH. 



It will be seen that many birds possess their 

 own particular species of parasite, which will die if 

 separated from its particular host. 



