150 THE WONDER OF LIFE 



develop in the water. This is, so to speak, arranged for 

 by making a nest among the leaves of bushes overhanging 

 the pools, and this nest breaks down at the appropriate 

 time, allowing the newly hatched tadpoles to drop into the 

 water. A number of leaves are held together by a deposit 

 of empty gelatinous egg-capsules, such as we sometimes see 

 in ordinary frog spawn — spheres of jelly without an egg 

 inside. It appears that the gelatinous envelope characteristic 

 of Amphibian eggs is adhesive when it is not in contact 

 with water. Thus the leaves are more effectively held 

 together. The cavity thus formed is filled up with a mix- 

 ture of full and empty egg-capsules, and then there is a 

 lid of empty ones on the top. It seems that the empty 

 capsules not only keep the leaves together until the tadpoles 

 are ready to drop out, but they form a protective shield 

 lessening the risk of drying up. Dr. Agar observed that 

 there was least mortahty in the more perfect nests, so that 

 the pecuharity of producing empty egg-capsules and the 

 habit of using them is just such a pecuharity as would be 

 fostered and fixed by Natural Selection. 



Defiance of Handicaps. — There is in many creatures 

 an extraordinary defiance of circumstances — a refusal to 

 admit handicaps. There is an order of jellyfishes, well 

 represented by the widely distributed green and blue 

 Rhizostoma pulmo, in which the mouth is normally closed 

 up by the hps so that only minute apertures are left along 

 the lines of suture. This is intelHgible, for the food is 

 microscopic and the pecuharity is long established. But 

 what are we to make of a case like the mouthless carp 

 described by J. W. Fehlmann, which hved and throve, 

 though its food-canal was mouthless and bhnd. That 

 was severe handicapping, but the fish refused to die. It 



