. A narrative history of the town of Cohasset, Massachusetts . emselves upon the snow and ice. The red snow alga which is still to be seen in the arcticregions was spread like a fine red powder upon the snow;and wherever any soil was exposed upon the ice or at theedge of the melting fragments, there was the alga mak-ing a red mould, just as it may be found nowadays some-times upon the wet ground of a cold spring day. Some higher kinds of alga had begun already their lifein the salt water along our shore. They were the sea-weeds clinging to the rocks. The snow alga was a tinyglobule, but the se
. A narrative history of the town of Cohasset, Massachusetts . emselves upon the snow and ice. The red snow alga which is still to be seen in the arcticregions was spread like a fine red powder upon the snow;and wherever any soil was exposed upon the ice or at theedge of the melting fragments, there was the alga mak-ing a red mould, just as it may be found nowadays some-times upon the wet ground of a cold spring day. Some higher kinds of alga had begun already their lifein the salt water along our shore. They were the sea-weeds clinging to the rocks. The snow alga was a tinyglobule, but the sea alga grew to be great ribbons wavingin the tide or bunches of Irish moss carpeting the dark brown varieties gathered nearer the surface ofthe water than the pale Irish moss, where some of it evendares to be exposed to the sun for a few hours at low most plentiful of these darker algae is the bladderseaweed or rockweed that fringes the rocks near the low-tide mark. It is so named because of the little empty 54 CLOTHED WITH VEGETATION. 55. Tip of one kind of rockweed, showing spore and air bladders, one half natural size. bladders in the stalks andthe margin of its frondshelping them to float. But not all the bladdersare empty, for the pimpledones contain the spores,the most important partof the plant. When theselittle germ cells are let outthey swim in the wateruntil they collide with somehard substance, where theystick. They never travelagain ; but in due timethey develop into a thallusthat becomes another sea-weed. A larger and more useful variety of these dark algaeis the kelp which grows in deeper water, but reaches up itsfronds on the top of a long stem to float in the swift cur-rents. The roots, which always grasp on stones or shellsor anything solid upon the sea bottom, are not roots forsupplying nourishment as the roots of trees, but only forholding their place. Their nourishment is absorbed fromthe water at any part of their surface. When storms ro
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Keywords: ., bookcentury1800, bookdecade1890, bookidnarrati, booksubjectbotany
