16 BULLETIN OF THE NATURAL HISTORY SOCIETY. 



and mud which subsequently became the solid rocks of the 

 Devonian age. 



The belief that the rings of growth in trees mark the 

 alternate periods of growth and repose which the returning 

 seasons bring to vegetation is not altogether dissipated, 

 though it has been attacked. Such a view of the source of 

 these annular rings has been called in question of late years, 

 and it has been stated that these rings are found in trees that 

 grow in tropical regions, where there are no changing seasons. 

 And further (that on testing the question by noting the 

 number of rings in certain young trees that have been made 

 the subject of observation) it has been found that these rings 

 are more numerous than the actual known years of the life of 

 the tree. 



We should remember, however, that within the tropics, 

 while there is no winter and summer, as with us, there are 

 in most parts of that great belt of the earth's surface certain 

 seasonal changes which, in their effect on vegetation, are 

 similar to the alternations of the seasons which we enjoy. 

 In some parts of the tropics there are two seasons in every 

 year, in others four : but in either case the trees would be 

 alternately stimulated to rapid growth, or left to mature the 

 wood and fruit whose growth had begun in the rainy season. 

 At the present moment (January) the woods on the uplands 

 and mountains in the West Indies are as brown and bare of 

 leaves as our own hardwood forests. 



Admitting, then, that these annular rings do indicate 

 seasonal changes, let us examine the condition of the logs 

 which may be found buried in the Devonian sandstones of our 

 city, to see if they exhibit any proofs of changing seasons of 

 the kind alluded to above. These logs occur in the lower 

 part of the formation, or terrain, and are often found in 

 clusters, as though they were parts of broken rafts that had 

 been ground and worn in their transit by water from the 

 interior of the country, before they were buried in the sands 

 of ihe bars along the course of the river, or at its mouth. 



