THE PLANT ECOLOGY OF THE COAST HELT OF NATAL. 375 



evenly distributed, produces a moist heat which is very 

 different in its physiological effects from the dry lieat of the 

 main river valleys of Natal. 



It is further necessary for our present purpose to examine 

 what differences are shown in the temperatui-e records for 

 different stations on the coast belt. Detailed tables were 

 printed in the first paper of this series^ and need not be 

 repeated. The different stations will be considered in order 

 from the southern end of the coast belt to the north. 



First of all, at Port Shepstone, near the border of East 

 Pondoland (Cape Colony), which is situated on the coast and 

 fully exposed, the average mean maximum is 78*4° F. and the 

 average mean minimum 59°, the average absolute maximum 

 96"5° and the average absolute minimum 44°. The average 

 greatest range here is 52*5°. The sea breezes temper the 

 extreme heat and the station is furthest away from the 

 tropics line. 



The next station is Umzinto, situated about seven miles 

 from the sea in a hot valley. The average mean maximum 

 is 81 '6° or 3"2° more than at Port Shepstone; the average 

 mean minimum is 56"2° or 2'8° less than at Port Shepstone. 

 The average absolute maximum is 101° and the average 

 absolute minimum 43°, giving a range of 58° as compared 

 with 52*5° for Port Shepstone. This comparison shows that 

 the valley type of climate can, to a certain extent, be dis- 

 tinguished on the coast belt as well as in the midlands. 



For Durban, which is situated about half-way between the 

 Cape Colony border and Zululand, on the coast, the fullest 

 records are available. The following are the averages : 

 Mean, 9 a.m., 69*9°; mean, 3 p.m., 73*2°; mean maximum, 

 79"2°; mean minimum, (31 "5°; absolute maximum, 98'9° ; 

 absolute minimum, 45'6°; absolute maximum in sun, 156" 1°; 

 absolute minimum in sun, 129'7°; mean amount of cloud, 

 9 a.m., 4"5 ; 3 p.m., 4*7; overcast sky being taken as 10. 

 The mean maximum is only 1"5° higher, and the mean 



' Bews. J. W., "The Vegetation of Natal." 'Annals of Natal 

 Museum," vol. ii, pt. 3, 1912. 



