182 Report of the Forest Commission, 



and vegetation has suffered no drawback from drouth or cold, it is barely possible that the 

 entire growth of that season will be represented by a single ring, but even this is doubtful, as 

 it is the thin sap which flows nearest the bark that nourishes the growth, and if an extra large 

 growth is formed the sugar and glutinous matter in the sap may thicken and impede the flow 

 of the more watery portion, and by forcing it into the ne<v inner bark cause a new growth; 

 but if, after a growing period, there comes a drouth sufficient to rob th« roots of the necessary 

 moisture, the sap in the wood thickens and the more watery seeks the inner bark, through 

 which it carries nourishment to the leaves. This is often insufficient, and many leaves fall and 

 others wilt, but with a fall of rain the supply of vital fluid is increased, the leaves brighten up 

 and the smaller ones grow. New life is imparted, and with this new life comes a new growth, 

 another ring is formed, and so on through the entire season Who living in the north has not 

 seen the leaves nipped by a frost after they were full and fall to the ground ? After a few warm 

 days and a warm rain new leaves start and the tree is soon in full foliage, but there has been a 

 check to growth and a new growth starts with the new leaf. Thus, one cause another checks 

 one growth and invites another, making a ring each time entirely independent of years." — 

 Saw-Mill Gazette. 



Mr. Austin Cary, of Bangor, Me., who, acting under instruc- 

 tions from the National Forestry Bureau, has been engaged in 

 the Maine forests in counting tree rings with a view to establish- 

 ing the age of the black spruce in that State, calls attention in 

 his report to certain facts which throw some light on this matter 

 of variable or retarded tree growth : 



" While carrying out the field work, which is behind all these 

 statements, facts were found proving the influence of the weather 

 on the growth of trees. In May, 1893, while at work on the 

 Androscoggin river, word came from Mr. J. A. Pike, of Berlin, 

 "N. H., that record was to be seen in the spruces of a series of 

 cold years which occurred in the early part of the century. This 

 was richly worth examination, and I immediately set about in- 

 vestigating the matter. Beginning the count of rings with the 

 bark, it was found on the first log examined that a number of 

 rings, being in that case the seventy -ninth to the eighty -third 

 from the bark, were very distinctly thinned. Continuing the 

 search, every tree was found to have a belt of thin rings in sub- 

 stantially the same position, these being reduced in some cases 

 almost to microscopic. 



" As soon as access could be had to books the history of the 

 matter was looked up, and it was found that the years 1812 to 

 1816 in Maine were very extraordinary years. The temperature 

 was unusually low as an average, and in 1812, 1815 and 1816, at 

 least, frosts or snows or both occurred in the summer. In 1815 

 and 1816 crops through the State were very seriously impaired, 

 and many people despairing of the agricultural prospects of the 



