CONCLUDING REMARKS. 497 



or a Radiate, or a Mollusk, or an Articulate, or a Verte- 

 brate, so clearly, that by patient study, the student of 

 nature is able to refer every one of to-day, and of by-gone 

 ages, to its appropriate type we are impressed with the 

 great truth, that in the Animal Kingdom and it is so in 

 all nature there is the greatest possible diversity, and 

 that in this diversity there is perfect unity ; and hence we 

 are forced to believe that all the animals of the past, and 

 all those of the present, have appeared in accordance with 

 a plan wrought out in the Divine Mind before the founda- 

 tion of the world. 



