356 FERDINAND W. HAASIS 



erect. The pine was growing on very poor soil, practically 

 outcrop. It had a rather weak stem 95 cm. long bent into an 

 arc of almost 90 degrees. 



Table 1 shows the results of the measurements, and table 2 

 the dates between which the growth in length ceased. From 

 the very few data collected, it seems that the plant forming the 

 ring-porous wood does, indeed, finish its wood growth at an 

 earlier date than that producing diffuse-porous wood. If this 

 be true, may there not be some relation between the diffuse- 

 ness of the latter' s growing season and the lack of the extreme 

 differentiation of tissue exhibited by the other? It is to be 

 noted, though, that the diffuse-porous woods grew much faster 

 earlier in the season than later on. In the case of the evergreen 

 conifer the growing season is prolonged as in the diffuse-porous 

 wood. 



There are needed a larger number of parallel observations on 

 this phenomenon; and the measurements should obviously be 

 more frequent in the very early part of the season. It should 

 not be overlooked that cessation of wood production does not 

 mean that growth has ceased, for bud formation, and in some 

 cases the maturing of fruit, continues considerably later than 

 wood growth. 



