1885.] A TALK ABOUT SOME TREE LEAVES. 355 



girder work, rind obtainable in lengths up to 60 feet. They were 

 very durable, and capable of sustaining great weights, but were 

 unreliable when exposed to white ants or marine insects. West 

 Australian tuart was a splendid quality of timber, very heavy and 

 dense in grain. It was unequalled fur scantling, and was largely 

 used for the heavy portions of railway trucks, etc. Blackwood was 

 strong and durable, being used for railway trucks and coach-building, 

 especially for wheels in light traps. It bends readily when steamed, 

 and was taking the place of American hickory. Once insects 

 obtained entrance to a building the timber of which was suited to 

 their palates the result was disastrous, and hence arose the necessity 

 of knowing the woods that they were least likely to attack. For 

 this reason he (Mr. Hack) had particularly noticed the red gum, 

 jarrah, karri, and Singapore cedar, the others mentioned not being so 

 proof either against insects or rot. 



A TALK ABOUT SOME TREE LEAVES. 



No. II.— Plates VI. and VII. 



OUR leaf album for this month illustrates how leaves of the same 

 family vary so decidedly as by themselves to afford no clue 

 to the species of a tree. In the seven figures depicted in the two 

 accompanying plates, the majority of the leaves have veins running 

 parallel to each other from a central stem ; in three at least the 

 outer boundaries of the leaf are nearly identical, yet these do not 

 characterize different species. A comparison of the plates with 

 those in our last issue shows how different varieties of the same 

 tree assume a leafage which admits of no family likeness. After 

 all, the flowers and fruit are the best characteristics of a tree. 



PLATE VI. 



Fig. 1 is the leaf of the species of Hawthorn, known as Cratmjus 

 sanguinca. Like other varieties of the family, it is stalked, narrow 

 at the base. The lobes or segments into which its outside area is 

 more or less divided, as well as the irregular toothed character of 

 its surface, are very distinct. 



Eig. 2. The leaf of the common alder, Alnus gluthwsa, has 

 a circular, "orbicular" shape, triangle-shaped towards the stalk, 

 with a hollow depression on top. The under side of the leaf is 

 hairy, or with a little down in the axil of the leaves. 



The finely-toothed leaf of the bird-cherry prunus. Primus padtis, 



