um at the same point, but the measuremente of Richardia show that while 

 the maximum for each dimension occurred betvveen midnight and the 

 middle of the morning, it did not occur at the same time, sometimes there 

 being a difference of 4 or 5 hours between the maximum for length and 

 that for thickness. The curve for length shows that considerable growth 

 took place, but as this is the result of the growth for the entire petiole, 

 which consists of the sum of the increments of growth of its zones, while 

 the growth in thickness is but that of a single zone. 



The curves are constructed having the abcissfe represent periods of one 

 hour each, the ordinates representing growth. One division of the ordi- 

 nates is used as a unit for the curve of length ; 3 being used for the curve 

 of thickness that the changes may be seen more readily as they are so 

 minute. The measurements were taken in millimeters, and as the instru- 

 ment recording growth in length multiplied 8 times, if the number of 

 spaces traversed by the curve be divided by 8, the quotient will be the 

 number of millimeters of actual growth. The instrument for thickness 

 multiplied by 40, and as three spaces were used as a unit, the number of 

 spaces traversed would have to be divided by 120 to give the growth in 

 millimeters. 



The effect of light on the germinating spores of marine alg.e. By 

 Melvin a. Brannon. 



Xotes on saprolegnia ferax. By Geo. L. Roberts. 



As to the sporangial development in the Saprolegniese, two important 

 theories have been presented— that of Strasburger and the more recent one 

 of Rothert. 



The former holds that the partition wall of the sporangium, in Saproleg- 

 nia ferax, forms at a thickened place in the protoplasm. This changes in- 

 to a cell-plate of varying thickness. The cell-plate is formed from a 

 strong light- refracting substance, yellowish in color, which is apparently 

 the same substance that is distributed in small granules in the protoplasm 

 of the thread. From this cell-plate, after a time, arises the limiting 



