INDIAN JL'EASSIC GTMNOSPEEMS. 



85 



APPENDIX. 



(Note on the Internal Structure of Conifer ocaulon sp.) 



Since the reading of the paper on " Some Indian Jurassic Gymnosperms," two sections^ a longitudinal 

 and a transverse, have been obtained from the block III. stem, Coniferocaulon sp. These shed very 

 little light on the general structure of the specimen ; the few facts that they contribute, however, 

 serve to confirm the view that it represents the remains of a coniferous stem. 



The transverse section passes through the stem below a lateral structure, evidently a branch-base *. 

 It shows that the stem is much compressed and imperfectly preserved, the breaking up of the tissues being 

 probably due in part to decay before petrifaction. The greater part of the pre 



ervcd 



(text 



The thickness 



of this layer is much greater on the side of the stem protected by the matrix of the block than on the exposed 



(text 



This indicates that the wrinkled surface shown in PI. 9. 



fig. 2 does not represent the true external layer of the stem, so that in the case of this specimen it is 



Text- fig. 1. 



t 



ti]oose(J surface. 



^ 



Coniferocaulm sp— Diagram of the transverse surface of the stem, showing the incomplete, 



imperfectly preserved woody axis x, with the surrounding layered tissues c. As the 

 diagram indicates, the woody structure is not equally clear throughout the axis. 



useless to compare the exposed surface with the external surface-features of Zamia Skinneri (according 



M 



to Seward, 24, pi. xiv. figs. 1, 2, & 3) or with those of Araucarias 01 ine ^oiymuc^u »c.t.uu ^ 

 to Fliche, 10, p. 7). Dr. Stopes reaches the same conclusion in the case of a British 



specimen (32, p. 56). . i j. * 



Neither the transverse nor the longitudinal section give any information concerning the nature of 

 the protuberances present on the wrinkled exposed surfaces; it cannot be determined whether they 

 have any connection with the vascular system or are merely cortical in origin. Dr. Stopes interprets 

 similar protuberances in the case of some Cretaceous specimens of Coniferocaulon as being due to the 

 presence of teredo-borings in the original structures (32, p. 55) , but this explanation does not hold, 



apparently, in the present case. . 



On the cut transrerse surface of the stem there are indications of zomng of the wood, though ,t 

 cauuot be determined whether the zones are seasonal or a result of petrifaction. In the transverse 

 section the wood presents a " coniferous " appearance, the jylem elements being small, polygonal, and 

 compactly arranged. The medullary rays seem to be uniseriate. In parts of the a..s. structure ,s 



structure 



Its position before sectioning was immediately above the 



shattered portion of the axis shown in the top left 

 SECOND SERIES. — ^BOTANY, VOL. YIII. 



N 



