Manchester Memoirs, Vol. li. (1907), No. 7. 3 



is evident that the double row is formed by the branching 

 of each strand in the single row. 



These scars are generally interpreted as having been 

 caused by the parichnos strands which are usually seen as 

 two small marks on the leaf scar, but are of somewhat 

 larger dimensions below the leaf cushion, as can be seen 

 in partially decorticated specimens. (See Fig. 2 in the 

 text.) In the specimen from which the sections were 

 taken, and also in some other specimens of Syringo- 

 dendron, the very large scars would appear to have been 

 due to subsequent growth of the parichnos strands as 

 they become nearly an inch in length. 



In the sections the periderm cells are much elongated 

 and sclerised, and are closely packed together. Towards 



Fig. 2. Sigillaria Bradi with bark slipped slightly to the right and 

 displaying Syringodendron markings. (After Weiss.) 



the patches of thin-walled tissue they become shorter, and 

 end in a layer of thick-walled cells, which forms a very 

 definite margin to the oval patches of tissue. (See Figs. 

 2 and 3 of the Plate) The cells in these patches are 

 fairly uniform and well preserved, thin-walled, and in 

 most cases devoid of cell contents ; but there are many 

 groups of cells with contents which may be the preserved 



