THE PALMS OF TIIE ANCIENT WORLD. 179 



much light on this subject. He took healthy 

 plants of about one hundred and seventy dif- 

 ferent species, among which were representatives 

 of most of the principal natural families, and 

 immersed them completely in a large tank of 

 water, where he kept them many months. In 

 that time many had perished and become com- 

 pletely disorganized, so that they could not in 

 any way be recognised ; others, though much 

 injured, and decomposed, were just recognisable ; 

 whilst some few had suffered little, if any 

 injury, from their long immersion. Of those 

 which best resisted the action of the water, the 

 pines and firs, and the ferns, were especially 

 remarkable for their perfect preservation, except 

 that the ferns all seemed to have lost their 

 8ori (or clusters of capsules.) This result 

 remarkably corresponds with the phenomena 

 of the coal strata, where the ferns are some 

 of the best preserved species ; and it is also 

 verj' singular that in vfery rare instances have 

 sori been detected on the fronds of fossil ferns. 

 Only one palm was submitted to the experi- 

 ment, and it withstood the immersion tolerably 

 Avell. Now, as a considerable portion, if not 

 all the coal strata, appears to have been depo- 

 sited at the bottom of lakes or seas, it will be 

 seen that before they would become covered to 



