250 Transactions. — Botany. 



residence. This locality is about 30 m. above sea-level. In 

 an area so small as Chatham Island, where every part is 

 within a few miles of the sea, and where the highest land 

 only attains a height of 286 m., it seems unlikely that there 

 should be any marked differences in temperature or rainfall ; 

 but Mr. W. Jacobs, who is intimately acquainted with the 

 high southern portion of the island, assures me that there the 

 rainfall is greater and the cold more severe than in the neigh- 

 bourhood of Waitangi. With regard to differences in tem- 

 perature, I think he is mistaken ; but, as for the rainfall, my 

 own very limited experience goes to confirm his statement. 

 Mr. Cox also writes to me of the greater rainfall in the neigh- 

 bourhood of Pipitarawai as if it were a well-known fact. 



The average rainfall at the meteorological station 

 is 30-4 in. (18). This is by no means high when compared 

 with many places in New Zealand, but the number of rainy 

 days is considerable. For example, 28"32 in. of rain fell on 

 192 days in 1890; 34-46 in. fell on 187 days in 1899; 

 24-29 in. on 185 days in 1897; 3217 in. on 194 days in 

 1896; 34-48 in. on 194 days in 1895; and 35-01 in. on 190 

 days in 1894. Thus light showers, very often of short 

 duration, are frequent, while heavy rain is exceptional, 

 although there is usually at least one fall during the year of 

 from 1 in. to 2 in. or even more during the twenty-four hours. 

 The rain usually comes from the north, consequently it is a 

 warm rain ; but, as is so often the case in many parts of New 

 Zealand, this is immediately followed by much colder rain 

 from the south-west, which has a direct effect on restraining 

 vegetable growth. The driest month is December, with an 

 average rainfall of 1*67 in., while the wettest is July, with an 

 average of 3-92. Taking the seasons of the year, summer is 

 the driest and winter the wettest, the figures being : Spring 

 (September, October, November), 6-11 in. ; summer (Decem- 

 ber, January, February), 5-97 in. ; autumn (March, April, 

 May), 7-76 in.; and winter (June, July, August), 8-83 in. 

 The character of the vegetation of any region depending more 

 upon the number of rainy days than upon the total rainfall, 

 the average number of rainy days for each month of the year 

 is of special interest ; these are : January, 11-7 ; February, 

 11 ; March, 12-1 ; April, 13-7 ; May, 17-8 ; June, 19 ; July, 

 23-2; August, 18-2; September, 16-8 ; October, 17-7; Novem- 

 ber, 14-7 ; December, 10-9. 



Turning now to the temperature, the mean yearly tempera- 

 ture is 51-4° Fahr., and the mean daily range 10-4° Fahr. 

 The extreme maximum and minimum temperatures for each 

 month are respectivelv : January, 73° Fahr., 35° Fahr. ; Feb- 

 ruary, 70° Fahr., 35°" Fahr.; March, 69° Fahr., 40° Fahr.; 

 April, 67° Fahr., 37° Fahr. ; May, 64° Fahr., 34° Fahr. ; June, 



