226 



DE. AGNES AEBEE ON THE 



(5) The detailed Structure of the Sporophyll. 

 Owinff to the absence of londtudinal sections it is difficult to elucidate the structure 



_ ^w vx^v. ^^^^:^ x^^ — "n 



of the sporophyll pedicel. Some of the transverse sections, which are slightly oblique, 

 show, however, that the pedicel bore two lateral sclerised pads. The sporophyll trace con- 

 sisted as usual of spiral tracheides. Transfusion elements can occasionally be recognised 

 in the neighbourhood of the bundle not far from the proximal end of the pedicel, but 

 they do not become abundant until the distal end is approached. At the base of the 

 upturned lobe of the sporophyll the transfusion tracheides are large and conspicuous, 



Text-fis. 3. 



A 



B C 





id B. Lepidostrohus oWiamius, Will., {.j>ilosus. Part of the dorsal surfaces of two sporo- 

 pliylls fiom a transverse section traversing the sporophylls ahove the apex of the cone axis. 

 A is from a very young sporophyll in -which no periderm has yet developed. B is from an 

 older sporophyll, in which there are indications of hypodermal periderm. Manchester 

 University ColL, E. 387. ( X 258.) 

 ej){dostr obits oldhamius. Will., f.pilosus. Part of the dorsal surface of a sporophyll lamina 



throu 



U. G. L. Colly 



C. 16. a. ( X 258.) Apparently a hj'podermal periderm is just heing initiated, and cracking 



has occurred during petrifaction along the plane of weakness caused hy the first formed walls. 



D. Pauloivnia imperialism S. & Z. (Scrophulariaceae). Part of dorsal surface of a calyx segment 



in transverse section to show hypodermal periderm for comparison with figs. B & C. ( X 258.) 



(7i = hase of a hair.) 



and tliey remain so throughout the entire length of the lamina. Here they form a 

 discontinuous sheath surrounding the small xylem group^ hut generally placed at 

 some little distance frcm it. 



The lamina was flat and leafy, hecoming narrower and thicker towards the tip, where 

 it was almost triangular in section. In the apical region the tissue was darker and more 

 sclerotic than at a lower level. An interesting feature was the remarkable hairiness of 

 the very young sporophyll laminae. The hairs, which are shown in PL 27. fig. 53, arose 



