SEA-ANEMONES : THEIR WEAPONS. 359 



(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 

 individually 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 S. dianthus or>S'. bell is into a narrow 

 parallel-sided glass cell, tilled 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 iu question with 

 much distinctness. 



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, 



