76' SYSTEMATIC ZOOLOGY TOR TEACHERS. 



And at last, manifested what one of the very minutest creatures in creation 

 can make, something to withstand the force of waves, and the wear and tear 

 of ages, a reef. But it has also been injurious to man, the most serious re- 

 sult being the sinking of so many ships. 



2. The coral polyp has had a great influence on the climate of the 

 Avorld, in the case of the Gulf Stream. This stream starts at the Gulf of 

 Mexico and, if its course were unobstructed, would go straight across • the 

 ocean and hit Africa. This would probably make the coast much warmer 

 than it is. But instead of this, it goes straight a little distance and then 

 strikes against, the Bahamas, which are simply coral islands, and is turned 

 in a north-east direction. It crosses the ocean and goes along by England, 

 and around the Scandinavian Peninsula. The stream is composed of hot or 

 warm water, and this is what makes Hammerfest as warm as New York, 

 though it is much farther north. 



3. The coral polyp has had influence upon commerce. It has made good 

 harbors. It has been bought and sold. 



SYSTEMATIC ZOOLOGY FOR TEACHERS. 



BY 



C. J. Maynakd. 



( CONTINUED. ) 



THE ANIMAL KINGDOM. 



* 



Although it is easy in most cases, to tell the differ- 

 ence between vegetables and animals, for example, between 

 a butterfly and the plant upon which it alights, there 

 are some forms of life which are so simple that no meth- 

 od has yet been discovered by which they may be dis- 

 tinguished as plants or animals. 



The Bacteria, for example, are about as often claimed 

 by zoologists as by botanists, and certain plant-like forms 

 exhibit flagellate movements. These also possess an "eye 

 spot "so called, which is quite sensitive to the light. Oth- 

 er similar forms also occur that so evidently exhibit char- 

 acters which are possessed by both plants and animals, 

 that we must consider that they live on the border line 



