136 



THE MICROSCOPE. 



Sept. 



youngest portions of the inner bark. They are quite 

 numerous, but are distributed without apparent order. 

 They are marked with numerous very fine pore-canals, 

 and very numerous and fine concentric lines. Abundance 

 of starch was found in the bark of Tsuga Ccmadensis. 

 The medullary ray cells and the tangential rows of large 



C/f 



Fia. 5. 



parenchyma cells, which occur at frequent and regular 

 intervals in the inner bark, were found to be especially 

 rich in it ; but, strange to say, no starch was observable 

 in the bark of Tsugu Mertensiana, although there were 

 a similar structure and arrangement of medullary ray- 

 cells and there were the tangential rows of large paren- 

 chyma cells, the same as in the other species. The very 



