54 Evolution and Adaptation 



Fleischmann again fails to point out that the geological 

 period in which the remains of archseopteryx were found, 

 is the one just before that in which the modern group of 

 birds appeared, and, therefore, exactly the one in which the 

 theory demands the presence of intermediate forms. This 

 fact adds important evidence to the view that looks upon 

 archaeopteryx as a form belonging to a group from which 

 living birds have arisen. That a number of recent paleon- 

 tologists believe archaeopteryx to belong to the group of 

 birds, rather than to the reptiles, or to an intermediate group, 

 does not in the least lessen its importance, as Fleischmann 

 pretends it does, as a form possessing a number of reptilian 

 characters, such as the transmutation theory postulates for 

 the early ancestors of the birds. 



The origin of the mammalian phylum serves as the text 

 for another attack on the transmutation theory. Fleischmann 

 points out that the discovery of the monotremes, including 

 the forms ornithorhynchus and echidna, was hailed at first as 

 a demonstration of the supposed descent of the mammals from 

 a reptilian ancestor. The special points of resemblance be- 

 tween ornithorhynchus and reptiles and birds are the com- 

 plete fusion of the skull bones, the great development of 

 the vertebrae of the neck region, certain similarities in the 

 shoulder girdle, the paired oviducts opening independently 

 into the last part of the digestive tract (cloaca), and the 

 presence of a parchment-like shell around the large, yolk- 

 bearing egg. These are all points of resemblance to reptiles 

 and birds, and were interpreted as intermediate stages be- 

 tween the latter groups and the group of mammals. In 

 addition to these intermediate characters, ornithorhynchus 

 possesses some distinctive, mammalian features — mammary 

 glands and hair, for instance. Fleischmann takes the ground, 

 in this case, that there are so many points of difference be- 

 tween the monotremes and the higher mammals, that it is 

 impossible to see how from forms like these the higher 



