40 HENRY B. BRADY. 



original length may have been it is impossible to say, but it 

 is seldom that pieces can be separated of more than an inch 

 or an inch and a half long. There is no evidence that it 

 has grown attached to any foreign body, though it is quite 

 possible that it may have done so. The branching does not 

 take place on any definite plan. Entangled amongst the 

 branches are often fragments of Polyzoa and other similar 

 organisms. 



Notwithstanding the flexibility and apparent softness of 

 the tubes, the proportion of organic matter they contain is 

 relatively very small. A mass of the " weed," thoroughly 

 washed to free it from soluble saline matter, and dried at 

 100° centigrade, left 87'6 per cent, of ash after ignition, and 

 this was almost entirely composed of silica. When living, 

 or in the fresh condition, the proportion of inorganic consti- 

 tuents would necessarily be a good deal smaller, but the 

 amount of moisture normally present in the test could not 

 be estimated from specimens which had been preserved for a 

 long period in alcohol. Under the microscope the appearance 

 of the tubes would give the idea that the chitinous or organic 

 basis formed a much larger proportion of the entire weight. 

 The arenaceous constituents are partly in the form of minute 

 angular sand-grains embedded in the chitinous envelope but 

 sufficiently exposed to give the surface a distinctly rough 

 appearance, and partly of the empty siliceous tests of E.adio- 

 laria, which abound in the mud of the sea-bottom in this 

 particular locality. 



Boiling in water has no appreciable effect on the organism 

 in the condition in which it has come into my hands, that is, 

 after long maceration in alcohol ; and moderately strong acetic 

 acid produces no perceptible change in it, even on the applica- 

 tion of heat. Heated in dilute hydrochloric acid (1 — 4) there 

 is at first a slight effervescence, carbonic acid being evolved 

 from a few minute Foraminifera built into the test rather 

 than from any calcareous cement, of which there appears to 

 be little or none. Under the influence of hydrochloric acid 

 most of the tubes break up, and eventually become entirely 

 disintegrated, owing apparently to the solution of the 

 organic matter. In those which remain the test appears 

 as a colourless sandy envelope, and the sarcode, which has 

 swollen to its original size, as a granular, transparent 

 brown mass, filling the cavity of the tube. With nitric acid 

 (1 — 4) the disintegration is much more rapid, and after a time 

 there is but little residue beyond the siliceous constituents. 



Treated with caustic potash and heated, the tubes are con- 

 |i(ierably disintegrated, but' \^ ^ different way, Those thaj; 



