Anatomie. 499 



It was also found that the action of boiling water upon 

 wood gradually delignifies the Xylem-fibres, and if it be suffi- 

 ciently prolonged the delignification becomes complete (Aes- 

 culus). Further, cold water operating for a longer period has 

 the same effect although in a less degree. It is shewn that 

 the water extracts from the wood a substance which gives the 

 same reactions as „lignin" when treated with phloroglucin and 

 thallin sulphate. A substance shewing a blue-green colour with 

 phenol HCl, the test for coniferin, is not extracted. Experi- 

 ments were made which shew that certain micro-organisms are 

 able to destroy the „lignin" substances thus extracted; those 

 extracted from the alburnum destroyed more readily than those 

 from the duramen. 



The author points out that the delignifying action generally 



ascribed to the secretion of an enzyme by certain parasitic fungi 



must, in view of these facts, be reconsidered. 



D. J. Gwynne-Vaughan. 



Tansley, A. G. and R. B. Lulham, The Vascular System 

 of the rhizome of Pterls aqullina L. and Pterls incisa 

 Thunb- var. integrifolia Beddome. (New Phytologist. 

 Vol. III. No. 1. p. 1. 1904.) 



The vascular anatomy of Pterls incisa var. integrifolia is 

 described, and it is shewn that the rhizome contains a soleno- 

 stele with a somewhat wavy outline. The leaf-trace at the base 

 of the petiole consists of a curved vascular plate iolded inwards 

 at its sides so as to form two deep lateral bays. These folds 

 are continued down the stem within the solenostele for some 

 distance below the insertion of the leaf-trace. The mouths of 

 the bays gradually dose up as they pass down until in trans- 

 verse section they appear as two vascular loops projecting in- 

 wards from the side of the solenostele. The type of stem 

 structure thus produced is then used by the authors to explain 

 the relation borne by the leaf-trace of Pteris aquilina to the 

 vascular System of its rhizome. 



In Pteris aquilina the leaf-trace consists of a number of 

 separate Strands which, however, are arranged so as to give 

 the outline of a continuous curved plate with two great lateral 

 bays or indentations closely resembling that in the variety of Pteris 

 incisa described above. It is shewn that the Strands that form 

 the lateral folds in the leaf-trace of Pteris aquilina are always 

 derived from the internal Strands of the rhizome, while those 

 that form the abaxial curved and the adaxial ends are given 

 off from the outer stelle ring. 



It is suggested by the authors that the lateral folds of the 

 leaf-trace here also should be regarded as continuing down 

 into the stem; precisely as in Pteris incisa var. integrifolia. 

 Here, however, they have for the most part become indepen- 

 dant of the outer System, and, moreever, those decurrent from 

 one leaf-trace are continuous with those from the leaf-traces 



31* 



