SEA- ANEMONES I THEIE WEAPONS. 859 



(and therefore the general visceral cavity) and the external 

 water. It follows that they are placed in perpendicular 

 rows; but I have not been able to trace any other re- 

 gularity in their arrangement. So far as I have seen, they 

 are so scattered, that one, two, or even more contiguous 

 intersepts may be quite destitute of a cinclis. I would not, 

 however, attach too much weight to this negative evidence, 

 since the animal has the power of closing them individu- 

 ally at will, and that so completely, that the most careful 

 scrutiny does not detect their presence. 



Perhaps the best mode of examining them is to put a 

 small specimen of the 8. dianihus or 8. bellis into a narrow 

 parallel-sided glass cell, filled with sea-water. After a 

 while the animal will be much distended ; the exhaustion 

 of the oxygen impelling the Anemone to bathe its organs 

 with as large a quantity of the fluid as it can inhale. The 

 pellucidity of all the integuments will be thus greatly 

 increased. A strong lamp-light being now reflected by 

 means of the mirror through the animal on the stage of 

 the microscope, an inch or a half-inch object-glass will 

 probably reveal the orifices in question with much dis- 

 tinctness. 



The appearance of the cinclides may be compared to that 

 which would be presented by the lids of the human eye, 

 supposing these to be reversed; the convexity being 

 inwards. Each is an oval depression, with a transverse 

 slit across the middle. When closed, this slit may some- 

 times be discerned merely as a dark line the optical 

 expression of the contact of the two edges; but, when 

 slightly opened, a brilliant line of light allows the passage 

 of the rays from the lamp to the beholder. From this 

 condition the lids may separate in various degrees, until 

 they are retracted to the margin of the oval pit, and the 

 whole orifice is open. 



The dimensions of the cinclides vary not only with the 

 species, and probably also with the size of the individual, 



