SECT. ii. CAULERPA. 219 



fertilizing spennatozoids and female germ cells. For 

 example, the Yaucheria sessilis consists of one long 

 branched cell; on the same side of it two swellings 

 appear near to each other, one of which elongates, 

 curls round like a horn, and is soon filled with snake- 

 shaped filaments having long cilia at their thin end, 

 with which they move rapidly both within the horn, 

 and after they come out of it into the water. They 

 are perfectly colourless, and correspond to the pollen of 

 flowering plants. The other protrusion which swells 

 into a globose germ cell, and which corresponds to the 

 pistil of a flower, contains a mass of green endochrome, 

 which, after being fertilized by the snake-like filaments, 

 becomes a primordial cell which has no motion, but 

 after having secreted a strong coating of cellulose, 

 it sinks to the bottom of the water, becomes a winter 

 or resting spore, and lays the foundation for a new 

 generation of plants. The resting spores produce new 

 forms, while the zoospores, like buds, only multiply the 

 type of the individual plant with all its peculiarities. 



The marine genus Bryopsis grows in New Zealand, 

 the Falkland Islands, and the seas about Cape Horn. 

 The species are mostly parasites on other Algse, and 

 produce innumerable zoospores. The genus Codium is 

 found in high latitudes, and appears under four different 

 forms on the British coasts ; one of these inhabits turfy 

 banks exposed to the spray of the sea, the others grow 

 in deep water, or on rocks never uncovered but at 

 spring tides. Species of this genus are found as far 

 south as Kerguelen's Land, and in most of the intervening 

 latitudes. The Caulerpas inhabit the warmer districts in 

 the northern hemisphere, and furnish, five species in 

 New Zealand. The numerous species afford almost the 

 whole food of turtles on many coasts, and other genera 

 furnish nutriment to a host of smaller animals. 2 

 2 ' Cryptogamic Botany.' By the Rev. M. J. Berkeley. 



