ACTINOLOGICAL STUDIES. 215 



to syringe the internal cavity through the mouth opening. 

 Otherwise, and if packed too soon into bottles, where 

 they lie one on top of another, a certain amount of 

 maceration takes place, and disappointment is the result. 

 The specimens were obtained as large as possible, and 

 usually possessed five or six circles of tentacles, arranged 

 in the usual manner. The "marginal spherules," or 

 "bourses chromatophores," were of the usual azure blue 

 colour, which varied considerably, however, in intensity. 

 They also varied much in number and size. The follow- 

 ing is a brief record of the essential features of the 

 internal anatomy of A. equina, in its normal condition : — 

 The oesophagus is usually much corrugated on its inner 

 surface, and produced at its lower end into two processes, 

 the oesophageal lappets. In the living condition the two 

 oesophageal grooves can be easily distinguished by the 

 colour, being of a greenish cast, quite different from the 

 other parts of the wall of the oesophagus. This distinc- 

 tion was observable in the specimens preserved in formalin, 

 when I afterwards commenced work on them a month 

 or so later. But I was compelled to transfer all my pre- 

 served material into spirit, owing to the extremely irrita- 

 ting action of the fumes of the formalin on the mucous 

 membrane of the nose and throat, and the painful effect 

 on the eyes. The spirit effectually destroyed this colour 

 distinction, and it became necessary to examine with 

 greater care in order to determine the oesophageal 

 grooves. For, although in most cases they were dis- 

 tinguishable by their greater depth, in many instances 

 this was not so, and it was only by careful examination 

 of the surface epithelium, confirmed by a transverse 

 section, that their existence could be with certainty 

 demonstrated. Oftentimes, from a cursory examination 

 only of the oesophagus, I formed erroneous conclusions, — 



