LCE aen 
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1900] Collins, — Seaweeds in winter I3I 
coast is the same at all seasons. Algae, as well as higher plants, 
include annuals, biennials and perennials. Nearly all of the latter 
have their periods of rest and periods of activity, but not all at the 
same seasons; some are quiescent during the summer and autumn, 
beginning a new growth in the winter, and reaching the highest point 
in the spring, others just the opposite. Some of the Laminariaceae 
produce a delicate frond at one season of the year, a coarse and 
leathery one at another; between the periods of activity is a period 
of rest, so that the two forms are sharply marked off. As the point 
of growth is at the base of the blade, the old frond is pushed up by 
the new, and the remains of a delicate frond may be seen at the tip 
of a coarse one, or a coarse frond with a delicate one forming at its 
base. 
Biennials are not common among algae, and not clearly under- 
stood; the great majority of species are annuals, but these annuals, 
like death, have all seasons for their own. Some, like Phyllitis, may 
be found at any month of the year; some, like Punctaria, only in 
spring; perhaps the largest number of annuals appears in spring and 
summer, when shallow bays are warmed by the sun, and swarm with 
life; in southern New England, with Dasya, Grinnellia, Agardhiella 
and others of our most characteristic forms; but there are many 
winter annuals, both on the northern and the southern coasts. Some 
of them, like Phaeosaccion, are short lived, found for a little over a 
month, then disappearing utterly; in March this plant produces 
incredible numbers of zoospores, minute cells each with its hour or 
two of active, seemingly voluntary motion, then sinking to rest: what 
happens then, how the species continues, no one knows, but the next 
February the delicate fronds are there again. 
The genus Callithamnion, taking it in the older sense, not as 
divided up at present, is almost a calendar of the seasons, from 
Antithamnion Americanum in February in Long Island Sound, to 
Callithamnion corymbosum in Massachusetts Bay in November, while 
the little Rhodochorton Rothii, continuously vegetating, begins to fruit 
in December and continues until March. 
Why one species selects one season and another another, why 
Antithamnion Americanum forms its wonderfully delicate and bright 
colored fronds before the waters begin to warm with spring, while its 
not distant cousin, Grifithsia Bornetiana, comes only with the mid- 
summer days, we cannot even guess; there seems to be no generali- 
