

MARINE BIOLOGICAL STATION AT PORT ERIN. 47 



from the full moon ; but the amount of solar energy 

 derived from the moon is sufficient, we are told, appre- 

 ciably to affect photosynthesis in the Phyto-Plankton. 

 The effectiveness of the moon in this photosynthesis to 

 that of the sun is said to be as two to nine, and, if that is 

 so, Kofoid is probably justified in his contention that at 

 the time of full moon the additional light available has a 

 marked effect upon the development of the Phyto- 

 Plankton. 



As on land, so in the sea, all animals ultimately 

 depend upon plants for their food. The plants are the 

 producers and the animals the consumers in nature, and 

 the pastures of the sea, as Sir John Murray pointed out 

 long ago, are no less real and no less necessary than those 

 of the land. Most of the fish which man uses as food spawn 

 in the sea at such a time that the young fry are hatched 

 when the spring Diatoms abound, and the Phyto-Plankton 

 is followed in summer by the Zoo-Plankton (such as 

 Copepoda), upon which the rather larger but still 

 immature food fishes subsist. Consequently the cause of 

 the great vernal maximum of Diatoms is one of the most 

 practical of world problems, and many investigators have 

 dealt with it in recent years. Murray first suggested that 

 the meadows of the sea, like the meadows of the land, 

 start to grow in spring simply as a result of the longer days 

 and the notable increase in sunlight. Brandt has put 

 forward the view that the quantity of Phyto-Plankton in 

 a given layer of surface water is in direct relation to the 

 quantity of nutritive matters dissolved in that layer. Thus 

 the actual quantity present of the substance— carbon, 

 nitrogen, silica, or whatever it may be — that is first used 

 up determines the quantity of the Phyto-Plankton. 

 Nathansohn in a recent paper* contends that what Brandt 

 * " Monaco Bulletin," No. 140. 



