6 



Dr. T. G. Halle— Equisetites Steins. 



Another specimen is shown, on a hirger scale, in Text-fig. 1. In 

 this case there is a cylindrical cast which is not quite vertical but 

 somewhat obliquely ascending. The cast is fairly thick, about 

 3'5 cm. in diameter, but only three iuteriiodes are ])reserved, with 

 a length of about 10 cm. together. To two of the nodes, tlie one at 

 the base and the second node above it, are attached horizontal 

 l)rauches, one to each node. The lower branch is very indistinct, 

 being seen, in its flattened condition, only from the side. The upper 

 branch lies on the upper surface of the piece of rock and can be seen 

 from above. Its flattened cast has a breadtli of 3-4 cm., and it can 

 be traced for a distance of more than 16 cm. from the main stem to 

 the edge of a piece of rock. Near the point of insertion of the branch 

 there is seen wluit must be taken to be a root protruding obliquely 

 downwards into the rock. Another root-like fragment is seen a little 

 below a node near the middle of the horizontal portion. Tlie main 



Fig. 1. Stems with rhizomes attached of Equisetites cohimiiaris (Brong. 

 Lower Estuarine Sandstone, Inferior Oolite : Peak Alum Works, Yorkshire 

 coast. 



interest of this specimen is in the occui'renee of creeping rhizomes at 

 different levels above each other arising from the same stem. On the 

 lower surface of the same piece of rock tliere is another horizontal, 

 flattened cast, not shown in the Figure, which is no doubt a branch 

 from the same stem, too, though the actual connexion is not seen. 

 The horizontal portion has a length of about 20 cm. ; then the branch 

 bends upwards to form a new aerial stem, in the same manner as 

 in the specimen figured in Phite II. 



The features here described seem to indicate not only that the 

 plants grew on the spot just as they are now found, but also that the 

 accumulation of the sandstone proceeded while the plants were still 

 growing. Tlie sending out of creeping, root-bearing rhizomes from 

 the upright stems at successively higher levels may be regarded as an 



