BY A. ir. S. LUCAS. 631 



While staying at the entrance to the Tuggerah Lakes, I 

 gathered the inflated capsules of the Wild Cotton Plant, Gompho- 

 carpus fruticosus R. Br., and made parallel analyses of the con- 

 tained gas, and of the air of the place. In the former I found 

 21% of oxygen, and in the latter 21-1%. This also shows that 

 the cavities were filled with air drawn directly from the 

 atmosphere. 



Portuguese Man of War. 



At the same place, I found a number of Portuguese Men of 

 War freshly thrown up on the ocean beach, and tested the gas of 

 the floats in the same way. It appeared to be identical with the 

 atmospheric air analysed at the same time. Here difi"usion seems 

 to be the pi-ocess by which the float is filled, the growth of the 

 cells providing the necessary cavity. The membrane appears to 

 be thin enough for diff'usion to be able to act. 



