68 Union Bay 



honey to the bees and home sites for the tule wrens, which, 

 together with the song sparrows, carried to their nests bill- 

 fuls of insects which they had taken from the stems and 

 leaves. The cattails and the loosestrife provided all the nest- 

 building material for the wrens, strips of leaves being used 

 for the exterior and framework, and the cattail down for 

 lining. The blackbirds nested among the denser growths of 

 the plant and fed on the many insects which clung to the 

 stalks and others which tunneled into the leaves. In the fall 

 the birds, released from their nesting duties, flocked together 

 and hunted insects all over the district. The marsh appeared 

 to me like a complex factory in which each creature did small 

 specific tasks, apparently unrelated, but all a part of a great 

 unified operation. 



I could not fail to notice how considerable a part the 

 submerged, or underwater plants, played in supplying the 

 items on the food list. When I saw them in the water they 

 appeared much like the land plants but, as might be ex- 

 pected, their structure is quite different. The land plants, 

 except for their roots, exist in a medium much lighter than 

 water, and much less able to provide mechanical support. 

 Consequently land plants must be strongly built in order to 

 withstand the rains, the strains caused by winds, and the 

 results of frost. On the contrary, ' water > is a much heavier 

 medium than air, its movement in shallow places is not 

 violent, and the support it gives to the plant is important. 

 The plant structure thus has fewer strains to endure and 

 smaller loads to handle, so that the underwater parts can be 

 weaker and less resistant than like parts of land vegetation. 

 I have often watched a plant when the waves from a passing 

 boat agitated it. As each part yielded to the swells the whole 

 became a misty graceful shape which changed to precise 

 erectness as the waves subsided. All of its delightful freedom 

 and underwater softness is lost if such a plant is brought into 

 the air. 



