304 Proofs of Ero/itfion. 



have broken tlirough and disclosed some of the rich treas- 

 ures beyond. 



First, Ave will notice some of the living links to be founds 

 not on account of Evolution, but in spite of it. These are 

 cases mainly of retarded or arrested development, which 

 will doubtless culminate at last in true types, the links 

 finally disappearing. The most interesting group of syn- 

 thetic types are the Ami)hibians — interesting because it 

 explains how we got out of the water, and into the woods. 

 The frog, whose transformations have already been referred 

 to, is the most familiar example of this group. The shores 

 of the early seas were doubtless the scenes of many equally 

 remarkable transformations. The creatures, ocean born, 

 Avere brave and hardy fellows, and bent on becoming land- 

 lubbers at any cost. All the Amphibians must be regarded 

 as links between the true water animals and land animals. 

 Their swim-bladders were made into lungs, their tins into 

 legs, their scales into hair and feathers. 



The living link between the egg-layers and the milk- 

 givers is the class of Marsupials, of which the Kangaroo is 

 a familiar example, which bring forth their young in an 

 imperfect state, the development being completed in a pouch 

 in front. In fact, the entire fauna of Australia may be 

 regarded as generalized types. Prof. Owen has described 

 two curious creatures discovered there, — the echidna and 

 ornithorhyncus, — still more primitive than the kangaroo. 

 They are pre-marsupials. They are both egg-layers, as no 

 other hairy quadruped is. Their eggs are placed, that of 

 the echidna in a pouch, as the marsui)ials carry their imma- 

 ture young, and that of the ornithorhyncus in a nest, and 

 there hatched. Like no typical egg-layer, they suckle their 

 young. The ornithorhyncus, which has a bill like a duck, 

 has bones resembling those of birds, reptiles, and seals. 

 What can all this mean if not descent Avith modification ? 

 Professor Huxley declares : " On the evidence of Palaeon- 

 tology, the evolution of many existing forms of animal life 

 from their predecessors is no longer an hypothesis but an 

 historical fact." 



The links between the animal and vegetable kingdoms 

 are abundant. The Pvhizopod is a fine example. It has 

 sensation, and seemingly i)urpose, though non-cellular and 

 inorganic. The polyp has no arterial or circulatory system. 

 It consists of simple layers of cells, and is propagated by 



