COCCOCHLORIS. 313 



Its substance, in the beginning Avatcry and pellucid, becomes 

 at a later period firmer and more intensely green. The frond 

 itself, subjected to the microscope, differs very considerably 

 in the different states of its developement. When it is green 

 and firm, the globules scarcely vary at all in dimensions, but 

 generally stand at the one hundred and twenty-fifth part of 

 a millimetre in the greatest diameter, and their form always 

 oblong, varies from elliptical to irregularly angular. Their 

 interior substance appears obscurely granular, and is always 

 more opaque in the centre. The vesicles are variable in form 

 and magnitude ; the smaller are mostly spherical, the larger 

 elliptical, all constantly surrounded by a hyaline border. 

 The smallest of all only differ from the other globules in 

 their spherical form and diaphanous margin ; and the most 

 nevertheless attain the fiftieth j^art of a millimetre in dia- 

 meter, and the largest have the twentieth part in their 

 greatest diameter. The larger these are, the more manifestly 

 granular is the structure of the interior substance: when 

 enclosed they scarcely equal the thousandth part of a milli- 

 metre. The diaphanous margin is equally manifest both in 

 the smaller and greater vesicles, and preserves the same pro- 

 portion. In the more delicate fronds, and those having less 

 consistence, being almost watery, the mass itself is constituted 

 of a colourless thin mucus, in which the oblong cylindrico- 

 elliptical, or rarely spherical globules, reaching from the two 

 hundredth to the one hundredth part of a millimetre in their 

 greatest diameter, hyaline or diluted green, scattered here and 

 there, appear, with areola3 intensely green, presenting a definite 

 suborbicular, or but irregular form, constituted of firmer and 

 more intensely coloured mucus, and filled with subrotund 

 globules, varying in diameter, from the thousandth to the 

 two hundredth part of a millimetre, and surrounded with a 

 narrow diaphanous margin. Intermediate forms are some- 

 times noticed, in which the mass itself, more diluted and 

 watery, gradually disappears, and the green areolae increased 

 in size, and at length confluent, assume finally tlie characters 

 of the older fronds." — Menegh. 



