231 



The tyloses give the Avood a characteristic appearance under the mi- 

 croscope. This can be seen in the photographs, though much of the 

 beauty is lost with the loss of color. 



Boulger (1) in his valuable AA'ork on wood mentions the sclerenchym- 

 atous tyloses of the Leopard-wood, and in describing the gross structui"e 

 of the wood, states that the sapwood is yellow, and that the tree has 

 heartwood squaring twenty inches, tliough only six inches show the 

 characteristic mottling. This would seem to indicate that even if all the 

 heartwood had t.vloses form, not all become sclerenchymatous. 



Leopard-wood. Rad. Sect. ( x 80 ) 



The wood is used in this country in the manufacture of musical in- 

 struments, and only the mottled wood is prized. Pieces of the mottled 

 were all that I was able to obtain, so I had no way of determining any- 

 thing in regard to the tyloses in the sapwood or unmottled heartwood. 



The formation of tyloses through the activity of the parenchyma, can 

 be readily understood, but nothing is known as to the cause of this activ- 

 ity in some woods, while in other woods tyloses are never formed. Then 

 again in most woods investigated nothing definite as to time of formation 

 is known. DeBary (2) states that in Robinia pseudacacia tyloses form in 



