1 6 Weiss, Phloem of Lepidophloios and Lepidodendron. 



and extensive lacunns reaching from one leaf trace bundle 

 to the next, these latter forming more solid bridges of 

 tissue uniting the woody tissues with the hard inner cortex 

 which is generally well preserved. Where the phloem 

 tissues are present as in the case of some of the prepara- 

 tions examined by Hovelacque, its appearance as figured 

 by him is not unlike that shown for Lepidophloios in 

 Plate I. of this paper, and Hovelacque identifies the 

 alternating larger and smaller elements as sieve tubes and 

 companion cells. This interpretation is, I think, perfectly 

 correct. 



The specimen of this Lepidodendron in the Manchester 

 Museum which shows the best preserved phloem, is a 

 preparation in the cabinet of the late Thomas Hick 

 (No. 6"]^ It was labelled by him " standard," and a 

 comparison of this slide with the figures of a specimen of 

 Lepidodejidron selaginoides reproduced by Williamson in 

 his Xlth Memoir,^ shows that it is a section from the same 

 stem which Williamson, and no doubt Hick, too, obtained 

 from their mutual friend, Mr. William Cash, of Halifax. 



A portion of this tran.sverse section is reproduced in 

 Fig. 8, and represents one bay of the phloem region with the 

 adjoining tissues. Here too, as in the previous preparations 

 described, a crack separates the primary wood from the 

 remainder of the tissues, and it will be noted in this speci- 

 men there has not yet been any secondary wood formed. 

 Thus the phloem region begins here a few cells from the 

 crack, and can be seen to consist of a very definite group 

 of larger elements, with only a few smaller ones, stretching 

 out to the tangentially elongated cells forming probably the 

 pericycle and endodermis. The smaller elements are often 

 arranged around, or partially around, the larger elements of 

 the phloem, but as these former are much fewer in number 



1 Williamson, W. C, rhil. Trans., i88i, Plate 51, Fig. 2. 



