Sunrise and Growth. 255 



A curious observation which had been made in a garden at Cape 

 Town in March, 1905, seems to bear on this point. A large, oval 

 grass plot was surrounded by a border of the Kei-apple plant, half of 

 which was to all appearances dead, the stems being white and leaf- 

 less, while the other half was green and luxuriant. The border had 

 been replanted several times, but without any success. The points 

 which appeared remarkable were these : — 



1°. Every plant in the decayed portion was affected to a 

 similar degree. There was no indication that any individual 

 plant had been protected by its position from the mischievous 

 action, whatever it might be. 



2°. At each end of the dead portion there was a length of 

 6 feet in which the plants were very poor, but were not alto- 

 gether leafless. Both of these lengths were on the south side of 

 the luxuriant half of the oval. Their symmetrical arrangement 

 could not be accidental, and suggested that the cause of the decay 

 was one which was constantly and gradually changing its position 

 from day to day. 

 On the morning of March 23rd the sunrise was being watched at 

 6h. 53m., and while the garden lay in the shadow cast by the Lion's 

 Rump, the sunlight out to sea was moving shorewards, till it eventu- 

 ally came up the gently sloping ground to where the oval border was. 

 At 7h. 37m. it reached that portion which was luxuriant, and three 

 minutes afterwards it was diagonally across the grass plot, almost 

 joining the ends of the decayed portion. Two feet out of the six-feet 

 lengths at each end were in sunlight as 8 o'clock struck and the sun- 

 light's further progress ceased. A shadow fell across the dead oval 

 border and lasted till gh. 50m. It was caused by a neighbouring house, 

 and at 9h. 50m. it joined the two extreme points as if with a straight 

 edge. The length of 6 feet at either end is at once the proof and the 

 result of the gradual variation in the incidence of the early rays, owing 

 to the sun's changing declination. The leafless state of the plants, it 

 is suggested, was due to their being in intense sunlight from ph. 50m. 

 onwards ; and without the rays of low ref rangibility to re-arrange the 

 chlorophyll-granules the stems turned white, indicating that the 

 granules had withdrawn to the innermost cell-walls away from the 

 mid-day glare. The chlorophyll bodies had not been deprived of 

 the requisites for developing the green pigment, but the granules had 

 accumulated on those surfaces which were least exposed to the bright 

 light. An examination of several neighbouring gardens showed the 

 action to be the same everywhere in the case of the Kei-apple plant. 

 Wherever the early rays did not reach it, and it was in full sunlight 

 for the rest of the day, its state was just the same. Cape local time 

 is that of Long. 30° E, or 46 minutes before sun's mean time. 

 This observation therefore elicits the fact that at sea-level, as well as at 

 an altitude of 4450ft., plants which do not receive direct sunlight 

 before ph. 4m. in March (true time) are very prejudicially affected, 

 while those that receive it as late as 8h. 6m. change colour. The 

 withdrawal of the chlorophyll-granules to a position of ' apostrophe,' 

 and the cessation of growth both of the peas at Pretoria and of the 



