SOME PLANTS FROM TROPICAL -SEA GARDENS 



565 



as far north as Bermuda and southern 

 Florida. It is rarely found in any great 

 quantity, yet occurs in considerable abun- 

 dance on old shells and pebbles, mostly in 

 ten or fifteen feet of water or less, in the 

 bays lying between the keys and mainland 

 of southern Florida. The actual height of 

 the plants is usually from two to four 

 inches. The elegant cup-shaped disk which 

 surmounts the graceful stalk is largely 

 reproductive in function, each of its radial 

 chambers containing at maturity, in the 

 present species, from 200 to 500 sub- 

 globose, firm-walled spores, scarcely visible 

 to the unaided eye, each of which produces 

 on germination a number of smaller motile 

 cells which are sexual in nature. At least 

 three other species of this genus occur in 

 the West Indian region. 



Among the larger green seaweeds of the 

 warmer parts of the earth are some that 

 are not calcified and of these the species of 

 Caulerpa — a dozen or more of them in Ber- 

 muda, southern Florida, and the Wesl 

 Indies — deserve especial mention. These 

 present themselves in a great variety of 

 graceful and attractive forms, some of them 

 suggesting delicate feathers, others looking 



like clusters of green grapes, the inflores- 

 cence of grasses, the twigs of cypress trees, 

 or sprays of running pine. They are found 

 in tide pools, on the roots of the red man- 

 grove in lagoons, and creeping on the sea 

 bottom down to a depth of a hundred feet 

 or more. Individual plants of some of the 

 kinds get to be four or five feet long. A 

 curious thing about them is that, although 

 they are plants of considerable size, no one 

 has yet certainly detected in them any 

 spores or other special reproductive organs. 

 They seem to maintain themselves by 

 simply continuing to grow at one end 

 while dying off at the other, or to propa- 

 gate their kind by accidentally detached 

 fragments. It nevertheless seems probable 

 that they produce some sort of minute 

 reproductive cells which have thus far 

 escaped observation and detailed descrip- 

 tion. Doubtless much remains to be learned 

 about the life history of the Caulerpas and 

 many of their relatives by some one so 

 situated that he can watch the living 

 plants continuous]}- throughout the year, 

 with a compound microscope and needed 

 accessories at hand. 



A species of J'ahinui, taking the form of a 



A GREEN SEAWEED, Caulerpa racemosa, that suggests bunches of grapes, photographed (not 

 in place) at the mouth of the Guanica Harbor, Porto Rico. (About one half natural size) 



