184 



BOYS AND GIRLS IN BIOLOGY. 



structure to make each one comfortable in his own 

 home. 



And now, before saying good-by, let us sum up what 

 we have done, and talk a little of what we may yet do. 

 We have studied pretty carefully what mercantile peo- 

 ple might call " samples " of those animals that have no 

 backbone — the invertebrates. (A vertebra is one of the 

 pieces which make the backbone.) But, in order to learn 

 about animals themselves, we had first to learn some- 

 thing about the plants upon which animals live. So we 

 talked of a " sample," or typical fungus, the yeast ; a 



GREEN PLANT, the PROTOCOCCUS \ and a FLOWERING PLANT, 



the bean. All plants belong under these three heads : 



FUNGI, GREEN PLANTS, FLOWERING PLANTS. 



The animals that have no backbone are classed under 

 five heads : protozoa, ccelenterata, annuloida, annu- 



LOSA, MOLLUSCA. 



Protozoa comes from two words, which mean first 

 and animal. All the first or simplest forms of animal 

 life are placed under this division of the invertebrates. 

 The amceba is the sample of protozoa that we have 

 studied. 



Ccelenterata comes from two words, which mean 

 hollow and bowel. The animals whose stomach and the 

 whole inside, hollow, or cavity of the body, are both in 



