CLIMBING THE ANIMAL TREE 33 



it oil the wall of our camp. This animal tree has a 

 straight trunk, and first come eight branches." 



" Ah ! Ah ! " cried Dodo. " Mother ! Daddy ! 

 Come and look ! Uncle is making each branch end 

 in an animal, so we can see with one peep where 

 they belong, and the little first animal that belongs to 

 the trunk hasn't any more shape than an ink blot ! 



*' What is that queer little spot, uncle ? Has it 

 a name ? ^Vli I now you are writing the name on 

 each branch," chattered Dodo. 



After everybody had looked at the sketch of the 

 animal tree, the Doctor hung it up on the door, and 

 said he would try to answer a few of their questions 

 about it. 



" These," said the Doctor, pointing to the lower 

 branches of the tree that he had drawn, "are the 

 animals which have no backbones, — Invertebrates, the 

 Wise Men call them, — and though I do not want 

 to trouble you with long names, you must try to 

 remember this one, because it is important and you 

 will meet it often in reading. 



" With these branches begin the lowest forms of 

 animal life. This little thing on the trunk that Dodo 

 called an ink blot is the very first form of animal life, 

 it is called a Protozoan, and it is really so small that 

 you could not see it without a microscope." 



" That is a pretty big name for next-to-nothing," 

 said Rap. 



" Yes ; but the name, like many of those the Wise 

 Men give, explains the meaning. It comes from the 

 Greek words protos (hrst) and zoon (animal), so among 

 ourselves we will call the trunk of the tree the first 



