8 Weiss, The Parichnos in the Lepidodendracece. 



sufficiently account for the retention of these parichnos 

 scars in all their distinctness after the fall of the leaves. 



That the parichnos scars continued their function for 

 some considerable time may be gathered from the fact 

 that in some old stems of Sigil/aria, even after the leaf 

 scars have disappeared, the parichnos strands can be 

 observed. The fossils formerly described as Syringodendron 

 are now known to be the decorticated stems of various 

 species of Sigillaria on which, though the leaf cushion can 

 no longer be seen, the underlying bark shows sometimes 

 the scar of the vascular bundle, but more generally only 

 two very large parichnos scars. These are indeed often of 

 such dimensions, being sometimes nearly an inch in length, 

 that one cannot help concluding that this organ was 

 endowed in some Sigillariae with powers of growth after 

 the fall of the leaf, and thus came very near the lenticels 

 in structure as well as function.* 



Some markings very like those of Syringodendron 

 were observed by Stur ('77) m Lepidophloios crassicmdis, 

 and also by Potonie ('99) in a LepidopJuoios in the col- 

 lection of the Prussian Geological Museum in Berlin. 

 According to Potonie's figure (223), two longitudinal 

 patches of tissue come into appearance in those parts 

 where the reflected leaf bases are in part broken away. 

 These scars are, as Potonie shows, patches of the parichnos 

 strands laid bare, and he considers that on the under 

 surface of the reflected leaf base the parichnos strands 

 come very close to the surface, and suggests that the 

 epidermis disappears at this point, and that the parichnos 

 strands are thus exposed. (See Text-Jig. 4.) I have 

 examined very carefully several sets of well preserved 



* For further information, see the papei of Miss K. Coward "On the 

 Structure of Syringodendron? Memoirs of the Manchester Lit. and Phil. Soc., 

 vol. 51, No. 7, 1907. 



