AS A FIELD OF MICROSCOPICAL RESEARCH. 25 



thrown upon many obscure points in the developmental history of 

 these subjects. Every fact impartially observed and faithfully re- 

 corded, although per se but of small value, yet in the aggregate 

 will prove that no more enticing path for the student of micros- 

 copic life can be offered than that which leads him through 

 the comparatively untrodden and, therefore, unreaped fields of 

 aquarian research. But I know that an apparently empty 

 Aquarium looks a joyless wilderness, and you will be anxious 

 to see it tenanted by more visible objects of interest ; and here let 

 me give you a word of caution, be content with still life. Crabs 

 and the Crustacea generally may be very amusing and lively 

 denizens of your tank, but they are fatal to that state of rest re- 

 quired for the development of microscopic life; they are like mis- 

 chievous puppies in a boot-room, and everything is overhauled by 

 them in a most ruthless manner. 



Eolis and the Nudibranchiate Mollusca devour everytbing, and 

 are to be avoided, unless they are especially to be studied, and 

 scarcely anything more favourable can be said for the Echinoder- 

 mata ; therefore the student must be guided by his subject of study 

 in stocking his tank. No harm will arise from putting in a few of 

 the hardier varieties of the Actinidaj, some Serpulse or Sabelke, and 

 such like objects, but my experience is decidedly against over- 

 crowding with anything ; the atmospheric condition of your 

 Aquarium, if I may use the term, must not be abused any more 

 tban that of our own. We may now consider your Aquarium in 

 healthy working condition, and the probable objects of interest 

 that may soon present themselves. One of the first may probably 

 be the multiplication of the Actinida^. This process takes place in 

 three ways, by gemmation most commonly, especially in Actinia 

 mesembryanthemiim, sometimes as many as thirty tiny well-formed 

 anemones being ejected from the oral opening of the parent at a 

 time. Again, buds may be given off from the sides, as in Sagartia 

 bellis. Multiplication takes place by fission, as may be observed in 

 the Plumose Anemone {Actinolobus dianthus), which often slides, 

 like a snail, along the glass front of your Aquarium, leaving in its 

 trail little pieces of its basal disc, which ultimately become young 

 anemones ; or fission may take place bodily, as in Anthea cereus, 

 which often divides into two or more parts by a gradually deepen- 

 ing sulcus, which, forming from crown to base, results in the estab- 

 lishment of two or more of these anemones where only one existed. 



