TBE DESCENT OR ORIGIN OF MAN 211 



as they would have been on well-stocked continents. This 

 group likewise presents many gradations, leading, as Huxley 

 remarks," "insensibly from the crown and summit of^the 

 animal creation down to creatures from which there is but 

 a step, as it seems, to the lowest, smallest, and least intelli- 

 gent of the placental mammalia." From these various con- 

 siderations it is probable that the Simiadae were originally 

 developed from the progenitors of the existing Lemuridae; 

 and these in their turn from forms standing very low in the 

 mammalian series. 



The Marsupials stand in many important characters below 

 the placental mammals. They appeared at an earlier geo- 

 logical period, and their range was formerly much more 

 extensive than at present. Hence the Placentata are gen- 

 erally supposed to have been derived from the Implacentata 

 or Marsupials ; not, however, from forms closely resembling 

 the existing Marsupials, but from their early progenitors. 

 The Monotremata are plainly allied to the Marsupials, form- 

 ing a third and still lower division in the great mammalian 

 series. They are represented at the present day solely by 

 the Ornithorhynchus and Echidna; and these two forms 

 may be safely considered as relics of a much larger group, 

 representatives of which have been preserved in Australia 

 through some favorable concurrence of circumstances. The 

 Monotremata are eminently interesting, as leading in sev- 

 eral important points of structure toward the class of 

 reptiles. 



In attempting to trace the genealogy of the Mammalia, 

 and therefore of man, lower down in the series, we become 

 involved in greater and greater obscurity; but, as a most 

 capable judge, Mr. Parker, has remarked, we have good 

 reason to believe that no true bird or reptile intervenes in 

 the direct line of descent. He who wishes to see what 

 Ingenuity and knowledge can effect, may consult Prof. 

 Sackel's works." I will content myself with a few gen- 



«> "Man's Place in Nature," p. 106, 



" Elaborate tables are given in his "Generelle Morphologle" (B, ii, s. cliiL 



