74 A MANUAL 



detail. Only, then, let me observe generally, that 

 every tank and glass ought to be emptied at least 

 once a fortnight (not necessarily throwing away the 

 water, which may be aerated and returned), and then 

 its interior is to be thoroughly cleansed by sponge 

 and glass-cloth, with as little disturbance to the ane- 

 mones which adhere to its sides as possible. I am 

 quite aware that we may keep anemones alive for a 

 considerable length of time without taking all this 

 trouble,* but I am equally certain that the more 

 often we go through this cleansing process the more 

 vigorously will our prisoners flourish, and the more 

 actively and beautifully will they " bloom." 



On the last items, the temperature and the lights 

 I need not enlarge. The ordinary heat of a sitting- 

 room will effect the former condition, and for the 

 latter a blind or shade, to ward off the summer sun, 

 is all that is necessary. For out-of-door tanks a roof 

 is needed to keep out the rain and protect the water 

 from the sun-light in the summer, and if severe frosts 

 are anticipated a more efficient shelter must be con- 

 trived, or the anemones should be removed into the 

 house during its continuance. 



If it be objected that these " conditions of exist- 

 ence" involve a considerable amount of trouble, I 

 can only admit the fact, and ask whether the pre- 

 servation of health — i. e. of the normal state of life 



* Mr. Gosse has a tank contidning live Actinice, &c., which has 

 not been disturbed for more than nineteen months. 



