222 BOTANICAL GAZETTE [march 



14 year old individual situated in the midst of the stand and only 

 a few feet from the "Wolf" tree. In fact, the "Wolf" tree may 

 have been one of the seed trees from which the stand had arisen. 

 The cutting, was made at approximately breast height, and already 

 on June 13 the annual ring exhibited some 90 new tracheids. 

 Three weeks later summer wood formation began. It follows that 

 up to July I, at least, we may expect many discrepancies in growth 

 to occur. The greater the difference in vigor between the two 

 trees compared, the greater will be the difference in the amount of 

 growth at that period. 



Others have noted the same growth irregularities between 

 different individuals of the same species. Among these is Robt. 

 Hartig (id), who expresses himself emphatically on this point. 

 I quote from his text as follows: 



Bei freiem Stande und directer Insolation des Baumes, besonders aber 

 des unbedeckten Bodens beginnt der Zuwachs in den unteren Stammtheilen 

 weit f ruber, als im geschlossenen Bestande und bei einem Boden, der entweder 

 beschattet (Nadelholzstand) oder von einer dichten Humusdecke bekleidet ist. 

 An 100 jahrigen Fichten, welche isolirt an einem Siidhange standen, war schon 

 am 1. Mai auf Brusthohe der Dickenzuwachs in Thatigkeit, an ebenfalls 

 frei stehenden gleich starken Baumen des Nordhanges auf nasskaltem Boden 

 war am 26. Mai noch kein Zuwachs bemerkbar. Im vollen Waldesschlusse 

 zeigten manche Fichten und Kiefern selbst am i . Juni noch ruhendes Cambium 

 auf Brusthohe, u.s.w. 



An excellent illustration is likewise afforded by Wieler's table 

 (table I). Trees I and II were in a 40 year st^nd, where they had 

 been subjected to similar siivicultural conditions. Wieler failed 

 to say whether tree II was bored on the north or south side, but 

 in either case the tracheid numbers are seen to be quite different 

 from those in tree I. Growth curves from neighboring trees under 

 similar conditions never coincide. Fluctuations are constantly 

 arising which upset the regularity of growth and for which no one 

 factor is responsible. 



Termination of secondary growth in aerial growth 



The autumn condition of the cambium was observed in tree I 

 both in 1912 and 1913, inasmuch as cuttings first began on this 

 tree on August 5, 191 2. The data given in table K include the 



