46 MICROSCOPICAL STUDIES. 



into the oesophagus and thence downwards. At this stage, ner- 

 vous excitement brings about a remarkable occurrence. The free 

 edges of the mesenteries close together and form an improvised 

 stomach by the approximation of the lateral lobes. If death has not 

 yet occurred, the powerful stinging-cells that load the central ridge 

 of the mesenterial filaments complete the work, while the associated 

 gland cells provide digestive fluid in plenty. It is surprising how 

 powerful and rapid this is in action. A few hours, three to four, 

 secure the complete digestion of a fish or a crab nearly as large as 

 the anemone itself. As the prey dissolves, this nutrient fluid is 

 permitted to leave the improvised stomach, and flows freely into the 

 various septal chambers, even too, into the tentacles ; the cells in 

 contact taking up what quantity they can. Any hard undigested 

 parts are ejected by the mouth. 



The sexes are usually separate. Both ova and sperm arise from 

 similarly placed glands lying a little way from the free edges of the 

 mesenteries (Figs. 2 and 3, gg and ov ). Many species are viviparous, 

 the young undergoing their early development within the septal 

 chambers, and only when their tentacles are just long enough arid 

 sufficiently provided with sting cells to capture prey, are they cast 

 out from the mother, by way of the mouth. Often have I obtained 

 these baby anemones by gently squeezing the parent's body, when, 

 one by one, minatures of the parent popped out through the mouth. 

 The Gem (Bunodes) ; the Beadlet (Actinia) ; and the Sand- 

 Anemone (Sagartia bellis) are examples in point. 



Classification. The anemones belong to the phylum Coelen- 

 terata, consequent upon having no definite tubular alimentary canal, 

 the mouth and oesophagus leading into a great bag-like cavity 

 without anal aperture. No cavities are developed within the walls of 

 the body ; neither is a ganglionic chain present, only an irregular 

 loose network of ganglia and nerves. 



The Coelenterata are subdivided into two classes ; a simpler, 

 without oesophagus or mesenteries the Hydrozoa ; a more complex, 

 with well marked oesophagus, and numerous mesenteries the 

 Anthozoa or Actinozoa, and it is to this latter division that the 

 animals we are now dealing with belong, and here I must remark, 

 that I am using the term Sea-anemone, in a wide sense, as equivalent 

 to the whole of the Anthozoa. 



Within the bounds of this class, many very divergent forms are 

 found. These are ranged in two sub-classes : 



I. The Hexactinia or Zoantharia and 

 II. The Octactinia or Alcyonaria. 



The first contains the true Anemones, most generally simple, rarely 

 colonial in habit, and which have their mesenteries in pairs in mul- 



