340 Notice of a Scientific Expedition. 



slate, yet the matter of substitution is a fine sandstone, while the 

 Calamites are generally found in the sandstone and are frequently 

 erect ; some of them are short conical stems which appear to have 

 been young plants whose growth was arrested before they came to 

 maturity. The Cactas are rare. 



Having completed our collections at the Joggins we bent our course 

 in a homeward direction. The first anchorage was at Grindstone 

 Island, at the head of Chepody Bay. It belongs to New Bruns- 

 wick. It is an inconsiderable island, but its quarries are valuable 

 and inexhaustible, and the grindstones are of a superior quality. We 

 found here the same species of vegetable relics as we had just ob- 

 tained at Cumberland Bay. We were however fortunate in discov- 

 ering several fossil trees belonging to the dicotyledonous order of ve- 

 getables. One of these trunks may yet be seen on the west side of 

 the island. It hes in the face of a cliff of sandstone which is about 

 fifty feet high. It reposes obliquely in the strata in a kind of trough 

 formed by the contortion of the layers. It is about twenty-five 

 feet above the base of the clIfF. This noble relic of ancient vegeta- 

 tion is uncovered for about forty feet, and probably twenty feet to- 

 wards its base is yet concealed in the rock and debris. There are 

 some obscure appearances of branches near its small extremity, so 

 that when these branches waved in the breezes of gone by ages, its- 

 trunk was full sixty feet in height. This trunk still preserves a con- 

 ical shape though in places it is flattened by compression. Its an- 

 nual layers, which are distinct, are of unequal thickness but this in- 

 equality is more evident when observed in the compressed portions 

 and it may be possible that a farther examination of different parts 

 of it will prove that the greater thicknes of some layers is the result 

 of compression, especially as the thickest ones are near the outside. 

 It is the opinion of some, if not all geological writers, that the veget- 

 ables of the coal formation enjoyed an equality of the seasons, or at 

 this period there was an equality or uniformity of temperature and 

 moisture, &ic. which favored an equality of vegetable growth, or that 

 the seasons were similar to those of tropical climates. It is well 

 known that the vegetables of that climate increase equally every 

 year, while those of temperate climates are influenced in their growth 

 by the temperature. In a cold season the annual layer is thinner 

 than when the season has been warm and moist. The diameter of 

 this trunk near its middle is about twelve inches, but many layers 

 have probably been removed in the process of decay, as its outside is 



