PLANTS AND ANIMALS 215 



lished in 1552, he established the group of 

 plant-animals or zoophytes. These organisms 

 were subsequently shown to possess but a 

 superficial analogy to plants, being thor- 

 oughly animal in all important respects. 

 Most zoologists and botanists since the time 

 of Wotton have been content to share the 

 problematical forms, either in common or by 

 sufiference, permitting them to be carried into 

 one camp or the other at the convenience or 

 pleasure of the student. A few years ago, 

 however, Haeckel advocated an arrangement 

 that met with some favor. He proposed to 

 place the simple intermediate forms together 

 under the heading Protista, a plan that time 

 shows has added nothing to clearness of con- 

 ception or convenience of study. 



Many writers believe that no characters 

 can be found that are universally diagnostic. 

 Dr. Asa Gray once said (1860) in connection 

 with an argument in justification of Dar- 

 winian evolution, that in regard to the two 

 classes of organisms, "no absolute distinc- 

 tion whatever is now known between them, giendine of the 

 It is quite possible that the same organism two kingdoms 

 may be both vegetable and animal, or may 

 be first the one and then the other." The 

 learned Dr. Claus,in his prorectoral address 

 before the University of Marburg in 1863 on 



