IOO 



BOTANICAL GAZETTE 



[FEBRUARY 



TABLE IX 



2 cm. 



5 cm 



10 cm, 



I 



2 



3 

 4 



5 



35-4 



39- 2 

 29.8 



29-5 

 25-9 



27.0 

 27.6 

 20.8 

 21 .7 

 18.9 



23.6 

 22 .8 

 18. 1 

 19.0 

 16.8 



20 cm. 



21-5 

 20.4 



16.5 



17.8 

 15.6 



50 cm 



19.4 

 18.2 

 15.6 

 16. 1 



14-3 



In this last case the sand was rather fine quartz, of yellowish color 



measured 



littoral 



dune formation was obtained in December, 1901, on the leeward slope 



of a high dune at Southport, Queensland, where 

 2 cm under the surface registered 58?4C. at 2 p.m. 

 was devoid of vegetation. 



formation 



The temperature of the dunes and the sand fields varies greatly. 



•e given. Of the 34 readings made under 



erases 



mean 



C. was obtained from dunes in Finland for a depth of 2 cm and 25?4 

 for c cm . Thp flvPfflffA rvf ta VAA 4,v m ^4- -c\. rt ™ ««+i<> IV A wa- 



The average of 



19 readings at Fremantle 



Q 



On the 



mea 



day within one hour the following series: 26.1, 25.8, 24.2, 27.9, 

 2 S -4. 26.3, 26.1, 27?oC. The atmospheric temperature at the 

 time was 25? 4, cloudiness 3, time December 7, 1902, 11:30 a. M- 

 12:30 P.M. 



must 



importance to the vegetation. Only a few observations have been 

 made by the writer to this end. One series will be given as a sample 

 of the extent to which such variations take place. The readings we« 

 made at Southport, Queensland, in December, 1901. 



In the light of measurements obtained the local distribution of 

 certain plants on the coastal sand formations seems to indicate that 

 the temperature factor is of the greatest importance for the mode of 



On the coasts of the Baltic 



the writer made frequent observations which tend to show 

 this. 



o 



At Ahus in Sweden there occurs on the upper beach an Amnio 

 phila-Elymus community, consisting of the following plants: 



communities 



