6 'J 

 gives also the dates of the beginning and end of e^ ilture 



period/ at the head of the column in which the data of that 

 particular culture period are ^ ^^2*4 ily.ced. The -econd line of 

 each table gives the culture numbers. "^hese numbers being 

 given the various cultures for convenl«=nce in reference, When 

 several kinds of stations occur at vu'z place, cultures of the 

 same niuaber cover approxiroatel^r the same time period. For in- 

 stance, at Baltimore, there is an exposed station, a covered 

 station, and a forest station. The two-week culttireSnumbered 

 6, for the exposed, coverecl , "and forest stations, at 'Baltimore 

 each grew from August 20 to September 3. In some cases, cul- 

 tures limiM*^ ' the same number for the exposed and c'-"'--"' 

 stations show a difference of a day in the lengths of their 

 respecti^'^e loeriods owing to the fact that •■ t was impossible 

 to take L.f;c.t^arer.ient s on both the exposed ajia oov-si ^ 1 ^iltrnt^j 

 on the same day. The' third line of all the tables gives the 

 length of each culture period in days, this number being ob- 

 tained for cii'xj ueriod by siibtracting the dates given at the 

 head of the column containing the data for that period. The 

 fourth line Jn all the ta'les gives the number of plants used 

 in obtaining the plant aeasurements . In all the tables, a dash 

 appearing in place of a rela ive value indicates that the data 

 necessary for calculating this relative value is lacking. An 

 asterisk Placed opposite a climatic Ixne^. shows tha"^ *"' " '"-^ex 

 was not plotted in the grpahs fto be described latere . This 

 is done in the case of most cultures v/here no plant data are 

 available for comparison with t'-r climatic values. The last 

 coluLin of each of the tables gives averages, for the station, 

 of the plant and climatic values presented. 



