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Avere into those living on the earth, in the water, and in the air. A 

 fourth group comprised all lower forms under the name of vermes. 

 With no previous researches to guide him, and but limited material to 

 study from, he produced this accurate division which all subsequent 

 investigations have only confirmed. For two tliousand years this 

 system was accepted. Up to the time of Linnpeus, no other successful 

 attempt was made, natviralists devoting their energies to discovering 

 and naming species. Linnaeus seeing the correctnesss of the principle 

 adopted, did not form a new scheme, but extended his researches and 

 made a further division into classes. [Addendum A.) 



It is not for the system that we are indebted to Linnaeus, but for 

 the firm foundation upon which he placed the science of natxiral history. 

 He it was who permanently formed the divisions of class, ordei', family, 

 genus, species, and perhaps his most valuable legacy was the method of 

 giving double names, based on the generic and specific characters — a 

 boon few properly realize. His system was piiblished in 1759, and for 

 the next sixty years naturalists devoted themselves to correcting and 

 improving upon it. The beginning of our century saw a marked advance. 

 The Linnajan system was then discarded and that which forms the 

 foundation of all present systems was adopted. In 1819 Cuvier gave 

 to the world the result of his laboui'S, which has continued with slight 

 modification to the present day. I place with it that taught by 

 Principal Dawson, he being our leading Canadian authority, and his 

 system being a fair example of the many in vogue at the present day. 

 {Addenda B. d; C.) 



Cuvier has selected the nervous structures as the means of detar- 

 mining his groups, at the same time giving due weight to the changes in 

 the other vital organs. At one end he separates all possessing a brain 

 and spinal cord extending throughout the body, and an internal skeleton, 

 from which they derive the name vertebrata. At the other end he 

 makes a group of all not formed on the bilateral plan, the parts radiat- 

 ing Irom a common centre, hence their name radiata. The remainder 

 is divided into mollusca and articulata. In the former the nerve centres 

 are scattered irregularly throughout their structure, all being connected 

 with two chief centres situated over the throat. In the other group the 

 nerve centres are arranged as a double chain extending the lensth of the 



