250 



the three varieties are shown in FIGURE 2 which was made from 

 drawings sent by Mr. Fawcett, of the Jamaica Botanical Gardens. 



That there are species which are not at all distinguishable, from 

 one another externally, but which vary in their physiological prop- 

 erties, is a recognized fact,* and the " bastard" logwood may sim- 

 ply be a new example of the same phenomenon. A parallel case 

 would seem to be furnished by the black locust {Robinia psenda- 

 cacia), the wood of which is described by Sargentt as being 

 " reddish, greenish-yellow or white, according to locality'' ; but the 

 yellow and white varieties occur side by side in at least one 

 locality. 



Summary. 



1. The most significant fact shown by elementary analysis of 

 the heartwood of typical specimens of logwood was the lower car- 

 bon content of the poorer wood, which may be due to lower pig- 

 ment content, hematoxylin being a compound containing nearly 

 twice as much carbon as oxygen. 



2. No morphological differences are discernible between red 

 logwood and " bastard" logwood in the young seedlings. 



3. Analyses of the various seedlings agreed too closely to warrant 

 any conclusion but that the metabolism of the seedlings was 

 essentially alike in the two varieties. 



4. The chemical differences between red logwood and " bastard" 

 logwood are very slight, and are probably due to differences in 

 amount of pigment. 



5. Extractions with various solvents gave solutions of different 

 colours, and also of varying orders of intensity in the several series, 

 indicating the presence of at least two pigments in varying pro- 

 portions, or a pigment radical in different combinations. 



6. This was confirmed by the fact that the order of colouration 

 intensity of a series of extracts was altered by diluting with water, 



7. Aqueous extracts of the two varieties of logwood gave differ- 

 ent reactions to acids, alkalies and other reagents. The differences 

 are parallel to those between a fresh aqueous solution of com- 

 mercial logwood " extract," and the same solution after it had 

 become discoloured on long standing. 



8. Attempts to determine the conditions of the discolourations 

 of solutions of commercial " extract," failed to yield definite resuks, 

 but indicated, in general, that darkness and air are favourable to the 

 change. 



* DeVries : Mutation stheorie, 1 : 122. 1901. 



\ Sargent : Catalogue of the forest trees of North America, 15. Washington, 1880. 



