INTRODUCTION. 11 



which may be dragged up by means of the hooked 

 grapnels used on many coasts by kelp burners, often 

 affords multitudes of Copepoda. The weeds should 

 be washed by agitation in a large tub of sea water, 

 and when the operation is completed, the water, after 

 being allowed sufficient time — a few seconds only — 

 for the subsidence of coarse material, is to be poured 

 off through a muslin net, on which the Copepoda, and 

 probably numerous other swimming animalcula, will 

 be intercepted. These may be cleaned while in the 

 net by repeated douches of sea water. The products 

 of the dredge, sand, mud, gravel, shells, &c, should 

 be treated in a similar manner before being thrown 

 overboard. I have no doubt that this method of 

 procedure offers by far the best chance of extended 

 acquaintance with the microscope life of the sea bed, 

 and that numberless new species and interesting forms 

 of life may be discovered by its means. 



The preservation of specimens is probably best 

 effected by alcohol in the form of rectified or methy- 

 lated spirit, but this agent has the disadvantages of 

 destroying many colours, and of rendering the animals 

 opaque by coagulating their albuminous tissues. 

 Still, among the numerous solutions which have from 

 time to time been recommended none are on the whole 

 so convenient or efficient. Perhaps the next best is a 

 solution of chloral hydrate (twelve grains to a fluid 

 ounce) in camphor water. As microscopic prepara- 

 tions, Copepoda are best mounted in some gelatinous 

 medium containing a very small quantity of glycerine. 

 Treated in this way mountings will keep in perfect 



