ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 595 



the embryo ; the cotyledon cannot certainly be traced back to one of the 

 primary quadrants, and does not seem to be always formed from the 

 same portion of the embryo ; the cotyledon does not show a definite 

 apical cell. 4. The root arises secondarily, is endogenous in origin, and 

 is practically always of epibasal origin. It grows from a single initial 

 cell. 5. The foot is very large in the young embryo, but later is almost 

 obliterated by the growth of the root. 6. No vascular cylinder is formed 

 in the stem region of the young sporophyte ; the vascular bundle of the 

 leaf is continued without interruption with the root, and the young 

 sporophyte appears bipolar, the leaf growing upward, the root downward. 



7. The bundle of the leaf petiole is concentric, that of the root diarch. 



8. The vascular system of the stem of the young sporophyte is built up 

 of the leaf traces alone. No strictly cauline bundles occur in the early 

 stages of the sporophyte. 



Fossil Marattiaceae.* — F. Krasser publishes diagnoses of the species 

 of Marattiaceae noted by the late Dionysius Stur in the Upper Trias 

 flora of Lunz. Of the seventeen species described, ten are new and 

 known only from Lunz. All the species belong to fossil genera (seven 

 in number), whicli are valid genera on the score of their sporangia. 

 The fossil Marattiaceae of the Keuper of Lunz thus show an extra- 

 ordinary degree of differentiation. 



Fossil Osmundaceae.t — R. Kidston and D. T. Gwynne-Yaughan 

 have published a third instalment of their studies of the fossil Osmund- 

 aceas. Inter alia, they give an account of Thamnopteris SchJechlendalii 

 Eichwald. They find the middle of the stele to be occupied by a mass 

 of short tracheids without admixture of parenchyma. Their view that 

 this is to be regarded as the equivalent of a pith is combated by E. C. 

 Jeffrey .% 



Stele of Osmunda cinnamomea.§ — J. H. Faull has examined much 

 material of the sporelings of Osmunda cinnamomea in all stages, and 

 sums up his results as follows. The cortical cells at the base of the 

 sporeling are inhabited by a fungus. Despite individual variations, in 

 no case is the transition from protostele to siphonostele effected by a 

 simple expansion, as has been claimed for Osmundaceae. There are 

 bays or gaps in the xylem near the nodes, which may result in enclosing 

 a " stelar " pith. Rarely, and only in adult stems, does the internal 

 endodermis and " extra-stelar " pith connect with the external endo- 

 dermis and cortex through the leaf-gaps. Internal phloem has been 

 found in unbranched adult plants, and this fact, together with the 

 absence of branching in the sporeling, is thought to indicate that 

 internal phloem and internal endodermis in this family have not " in- 

 truded " through branch gaps. The general conclusion is that the stele 

 of the existing Osmundaceas is a " reduced amphiphloic siphonostele," 

 and that it is consistent with Jeffrey's theory of the origin of the 

 siphonostele and the homology of the pith. 



* SB. k. Akad. Wiss. Wien, cxviii. (1909) pp. 13-43. 

 t Trans. Roy. Soc. Edinburgh, xlvi. (1909) pp. 651-67 (8 pis.). 

 X Bot. Gaz., 1. (1910) p. 74. 



§ Trans. Canadian Inst., viii. (1909) pp. 515-34 (3 pis.). See also Bot. Gaz., 

 xlix. (1910) pp. 475-6. 



