IV] FOSSIL NUCLEI. 87 



or canal. The contents of cells in some cases closely simulate 

 starch grains, and such may have been actually present in the 

 tissues of a piece of a fossil dicotyledonous stem described by 

 Thiselton-Dyer from the Lower Eocene Thanet beds^ and in 

 the rhizome of a fossil Osmunda recorded by Carruthersl 

 (Fig. 42, B, p. 214.) 



Schultze in 1855' recorded the discovery of cellulose by 

 microchemical tests applied to macerated tissue from Tertiary 

 lignite and coal. With reference to the possibility of recognising 

 cell contents in fossil tissue it is interesting to find that 

 Dr Murray of Scarborough had attempted, and apparently 

 with success, to apply chemical tests to the tissues of Jurassic 

 leaves. In a letter written to Hutton in 1833 Murray speaks 

 of his experiments as follows : — 



" Reverting to the Oolitic plants, I have again and with better success 

 been experimenting upon the thin transparent films of leaves, chiefly 

 of Taeniopteris vittata and Cyclopteris, which from their tenuity ofier fine 



objects for the microscope By many delicate trials I have ascertained 



the existence stiU in these leaves of resin and of tannin 1 am seeking 



among the filmy leaves of the Fucoides of A. Brongniart for iodine, but 

 hitherto without success, and indeed can hardly expect it, as probably did 

 iodine exist in them, it must have long ago entered into new com- 

 binations*." 



Apart from this difficulty, it is not surprising that 

 Dr Murray's search for iodine was unsuccessful, considering 

 how little algal nature most of the so-called Fucoids possess. 



Some of the most perfectly preserved tissues as regards the 

 details of cell contents are those of gymnospermous seeds from 

 Autun. In sections of one of these seeds which I recently had 

 the opportunity of examining in Prof Bertrand's collection, the 

 parenchymatous cells contained very distinct nuclei and proto- 

 plasmic contents. In one portion of the tissue in the nucellus of 

 Sphaerospermum the cell walls had disappeared, but the nuclei 

 remained in a remarkable state of preservation. The cells 

 shown in fig. 42 are from the ground tissue of a petiole of 



1 Thiselton-Dyer (72) PI. vi. ^ Carruthers (70). ^ Sohultze (55). 



* I am indebted to Prof. Lebour of the Durham College of Science for the loan 

 of this letter. 



