JEFFREY. — ARAUCARIOXYLON TYPE. 547 



of Sanio in all cases are shadowy and didlcult to discern, although 

 they can be made out by the eye of expectancy. Agnthis Bulivillii, 

 material of which was received from the Botanic Garden at Buiten- 

 zorg, Java, through tlic kindness of the late Dr. M. Trcub, Director, 

 proved in this respect to be most favorable. P]ven here, however, 

 in the most favorable instances, the bars of Sanio are scarcely as well 

 developed in the wood of the cone, as they are in the least favorable 

 species of Araucaria, which has been examined and figured in the pres- 

 ent connection, \iz. A. imbricafa. It does not seem necessary on that 

 account to present illustrations of Agathis. A. amtralis shows bars 

 of Sanio, less distinctly than any other species examined. No indi- 

 cation whatever of the existence of bars of Sanio has been found in 

 the seedling of A. australis, although it has been examined in detail 

 with considerable care. 



Finally attempts were made to discover bars of Sanio in the region 

 of the primary wood in species of Araucarioxylon. Here on account 

 of the generally bad state of preservation of the material and also 

 doubtless on account of the delicate nature of the bars in this region, 

 even in living representatives of the Araucariineae, the results were 

 entirely negative. It is well perhaps at this point to indicate the best 

 method of demonstrating bars of Sanio in the wood of cones of living 

 species of the Araucarian tribe. Haidenhain's hematoxylin was 

 found most useful for bringing out the structure in question ; but care 

 must be taken to have both the hematoxylin solution and the iron 

 alum solution perfectly fresh. The sections after being subjected 

 to the action of the iron alum for ten or fifteen minutes are washed 

 carefully and rapidly in three changes of distilled water. They are 

 then allowed to remain in fresh distilled water for half an hour or 

 more. Next they are treated for some time with hematoxylin solu- 

 tion of one fourth of one per cent strength. In this they remain for 

 some time, up to half an hour. Unless the solutions are cjuite fresh 

 they will become fatally overstained. After a washing or two in 

 distilled water, the sections are transferred to a very dilute aqueous 

 solution of safranin ami allowed to remain for several hours or over 

 night. If the process has been successfully carried out, the bars of 

 Sanio will appear as intense blue transverse banfls on the red back- 

 ground of the lignified cell wall of the tracheid. The}' are most easily 

 seen nearer the ends of the tracheary elements, just as is the case in 

 those coniferous woods where they are abundantly and normally 

 present in the mature tissue. 



It was considered that the appearances described above in connec- 



