228 



tial lines, and in regular radial rows, having blind ends, as they seem to 

 start and to stop anywhere. The tangential rows branch, the branches 

 running into other rows or joining with the cells around trachea?. Some- 

 times the tangential and radial rows are so regular that they give the 

 wood a cross-ljarred apiiea ranee. 



The medullary rays consist of very narrow, long cells, the long diam- 

 eter running in a radial direction. They are from one to four cells wide, 

 the more common number being two. They are from about tifteen to 

 fifty cells in height, though an accurate count could not be made, due 

 to the presence in every ray of larger sclerenchymatous cells. One or 

 more of these sclerenchymatous cells, having fairly thick walls, occur in 



Leopard-wood. Trans. >Sect. ( x 300 ) 



each ray, either at the end or throughout its height. In all cases a 

 sclerenchyma cell occupies the place of two to four of the regular 

 parenchyma cells and seems to be the result of the merging of a number 

 of the parenchyma cells. They are seen to best advantage in the tangen- 

 tial section. 



In a sunilar way the radial I'ows of parenchyma, though as regular 

 in their formation as the rays, are easily distinguislied fiom the rays by 

 their greater size and sclerenchymatous Avails. 



