Ecology of Marcus Island — Sakagamx 
83 
tioned also that the fringing reef may serve to 
a certain degree as a physical barrier against 
the immigration of various terrestrial organisms. 
CLIMATE 
Thanks to the occurrence of a weather sta- 
tion, which initiated its postwar activities in 
April, 1951, we possess a rather precise picture 
of this mere heap of sand and pebbles in the 
vast ocean. Means of maximum, mean, and 
minimum daily temperatures during my stay 
were 25.9°, 22.7°, and 21.0° C., respectively; 
the average annual trends of various climatic 
factors are shown in Table 1. From these data, 
Fig. 1. Marcus Island. Drawing based upon a map used in the Observatory, show- 
ing Messerschmidia and Pisonia (dots), papaya (triangles), coconut palms (crosses), 
buildings (including ruined ones). Minute dots denote the density of Ipomoea. a , Office 
of weather station; h, lodging house; c, harbor; d, ruined barracks. 
