IN CEYLON. 55 



The stratification exhibited by the deposit is due to the 

 variation in the colour of the different parts, and may be 

 detected in the globules formed within the parenchymatous 

 elements. 



The maximum quantity of gum-resin is seen in our blackest 

 woods, such as j}. Melanoxylon and D. Ebenum, and the mini- 

 mum in our whitest woods, such as D. insignia and D. hirsuta. 



The mottled colour of some timber specimens is due to the 

 gum-resin being almost limited to the medullary ray cells ; 

 these are packed with the brown-coloured substances, while 

 the neighbouring elements, including vessels, are nearly 

 empty. This feature is noticeable in our lighter coloured 

 woods, such as D. Gardner i. D. sylvatica, and D. insignis. 



*- + * . 7 ^ / _. f ^ _ . . O -^. 



The appearance of the material in the vessels may occur 

 unaccompanied by any change in the physical properties of 

 the wall, and the fuchsin and safranin reagents can still be 

 used with advantage, even when the elements are entirely 

 filled with the coloured substances. In many cases the 

 coloured substances impregnate the walls of the elements, but 

 only in few cases do the walls show signs of decay. 



V. SEEDLINGS, fa fT^~ vj* 

 In the development and anatomy of the seedlings several 

 interesting points have been determined, and a synopsis ig 

 here given. The characters of seedlings have not yet found 

 a prominent place, if one at all, in systematic monographs. 

 The occurrence of specific and generic characters in the 

 developmental phases, in the morphology of the cotyledons 

 and epicotyledonary leaves, and in the behaviour of the leaf 

 traces must serve as the reasons for their inclusion in the 

 present work. 



The importance of seedling characters for systematic 

 purposes has of late been discussed by various botanists. 



Miss Sargant* has stated that no doubt remains as to the 

 systematic value of the indications given by the vascular 



* Ethel Sargant. The Origin of the Seed-leaf in Monocotyledons : New 

 Phytologist. Vol. I.. No. 5. 1902. 



