438 Zoological Classification, 



Dickson, of Kingston, one half were collected from an area of 

 one hundred acres. The trees which we find most generally in 

 our woods are the oak, beech, maple, iron-wood, elm, birch, ash, 

 pine, hemlock, tamarack, cedar, poplar, and bass-wood. All 

 these trees attain to a considerable size, and grow to a greater or 

 less extent, in all parts of Canada, except on the coast of Labra- 

 dor, where the only trees that thrive are the white birch, the fir, 

 spruce, beech, and one of the varieties of pine. The trees of 

 smaller growth common to all the country are the hickory, wil- 

 low, alder, wild-cherry, dog-wood, sassafras, and a few others. The 

 black-walnut, tulip-tree, and chesnut are confined exclusively to 

 the western peninsula. Oak and elm are more abundant and of 

 better quality in Canada West than in the eastern part of the 

 province ; but all the other woods attain greater perfection in 

 Canada East." * Now all these trees have their own species of 

 insect persecutors. How many species prey upon each tree ? 

 When does each species deposit its eggs, and in what part of the 

 tree? when is the larva produced, what is its form, and upon what 

 part of the tree does it feed ? how long does it remain in the larval 

 state ? what is the form of the chrysalis,and when does the imago ap- 

 pear ? and lastly ,is there any method of protecting the tree? When all 

 these questions shall have been answered, our entomologists, of 

 which we have now a few good men and true, will have performed 

 a great work. It seems almost impossible to protect a forest 

 against an insect foe, but who knows what may be achieved by 

 patient study ? By accumulating facts, sooner or later, a means of 

 protection may be discovered. At all events, when our interests 

 are threatened by an enemy, it is well to know all about him, 

 his numerical strength and the plan of his operations ; without 

 knowing these we can never hope to discover his weak points. 



ARTICLE XLI. — Zoological Classification ; or Coelenterata and 

 Protozoa^ versus Madiata, 



The recent appearance of the fourth volume of Agassiz's mag- 

 nificent contributions to the natural history of North America, 

 and of various manuals, text-books, and articles, on the sub-divi- 

 sions of the Radiata of Cuvier, have forcibly attracted our atten- 



* Descriptive list of the principal Canadian Timber Trees. By Charles 

 RoBB, 0. E. Canadian Journal, 2nd Ser., Vol. 6, p. 29. 



