Manchester Memoirs, Vol. xiv. (1901), No. 1. 19 



the purpose of storing food material to meet the require- 

 ments of cambial activity. Such elements we have seen 

 occur in considerable numbers in the specimen of Lepido- 

 phloios in which secondary thickening was taking place, 

 and might be more numerous in a specimen of Lepido- 

 dendron provided with an active cambial layer. This view 

 is also supported by the great meristematic activity 

 displayed by the phloem in the specimen of Lepidophloios 

 recently sent me by Mr. Cash, in which secondary growth 

 is just commencing. 



Until it is disproved that the cells of this phloem 

 region are of such a nature as not to be able to effectively 

 conduct and store organic material for the use of the 

 secondary meristem we must look upon it as functionally 

 representing the phloem, though it may differ from it in 

 construction. But as a matter of fact it does not seem to 

 differ materially from the phloem of recent LycopodiacecB 

 except in such particulars as are probably connected with 

 the absence of secondary thickening in recent Lycopods 

 and the consequent diminished need of storing organic 

 material within the stele. 



That some of the elements of the phloem region may 

 have been of the nature of laticiferous cells or may have 

 united to form mucilage ducts is, of course, quite con- 

 ceivable, even when the bulk of the elements made up a 

 true phloem. There seems to me, however, to be no 

 evidence of such secretory tissue in this region in well 

 preserved specimens of Lepidophloios and Lepidodendron. 

 In the outer cortical tissue, however, in both genera just 

 inside the periderm there can always be seen true 

 lysigenous glandular patches. These have been figured 

 by Seward for Lepidophloios, by Bertrand in Lepidodendron 

 Harcourtii, and they are also clearly visible in the section 

 of Lepidodendron selaginoides, from which the phloem 



