34 



HARDWICKE'S SCIENCE- GOSSIP. 



[Feb. 1, 1867. 



between the surfaces, and with this success com- 

 menced. A specimen, once inserted between the 

 glasses, could be} kept in good working order for 

 several days, a power of £ employed, and the con- 

 densers brought to bear with great convenience. 

 Added to this, the bath was readily reversed, and 

 that without dangerto the object. The slimness of 

 the glass also proved of further value, as, in con- 

 sequence of its flexibility, the sides could be brought 

 into contact without fracture ! 



Fig. 28. Disc of Melicerta ringens. The arrows show the 

 direction of the currents. 



On using the £, my attention was immediately 

 drawn to the great extent of the ciliated surfaces ; 

 the whole of the upper portion of the creature 

 seemed to be alive with their action. Not only were 

 the lobes fringed with cilia, but a second row was 

 found to exist on the inner surface of the two upper 

 lobes, the action of which was for some time mis- 

 taken for currents of water. This inner series is in 

 connection with the two finger-like valves, which 

 protect the entrance to the gullet ; and its especial 

 office is to pass forward to them all particles 

 brought within its influence ; these are then in- 

 spected by the cilia covering the valves, and if 

 considered lit, are allowed to enter the passage 

 leading to the gizzard. From this a ciliated surface 

 extends to the lintel or chin over the mould ; its 

 action creates a strong back current, by which all 

 that is unfit for food is thrown off, with the excep- 

 tion of certain particles, which appear to be selected 

 for the pellet ; these are directed to a side-channel 

 lcadiug to the mould. Here the cilia are again seen 

 in full activity — its hollow may be said to be lined 

 with them ; and it is by their action that the 



spinning motion of the pellet is set up and con- 

 tinued. 



The following drawings will serve to assist the 

 description: — Fig. 28, exhibits the inner row of 

 cilia, the action of which is indicated by the arrows. 

 The finger-like valves are shown; and over the 

 mould is seen, in profile, the surface by which the 

 back current is produced. Fig. 29 gives a side view 

 of this surface («), the direction of the current 

 being shown by the arrows ; and the channel 

 leading to the mould is seen at b. 



Fig. 29. Profile of disc of Melicerta ringens. 



It is very possible that all which has been de- 

 scribed has been noticed before, but it is equally 

 possible that it has never been so clearly and con- 

 tinuously observed. Nothing that I have ever seen 

 has surpassed the definition of the mould under the 

 £, assisted by the condenser; the eye seemed to 

 enter within its walls, and there to witness the 

 coming in of the first particles after a pellet had 

 been deposited. Curious, indeed, was the action of 

 the cilia, playing like fingers, with the nucleus, and 

 turning it first in one direction and then in another 

 till the rotatory motion was commenced. My 

 pleasure was indeed of the highest degree ; and this 

 paper is written with the hope that it may be the 

 means of adding to the pleasure of others, and not 

 only this, but that, while contemplating these 

 wonders of creative power, our minds may bow in 

 silent adoration of that Great Being for whose 

 pleasure more especially " they are and were 

 created." 



The manufacture of this kind of bath is so simple 

 that a few instructions are added, by which any one 

 of moderate ingenuity may make several in the 

 course of an hour or two. 



The requirements are a stock of thin glass, a 

 sharp writing diamond for cutting it, and a tin 

 trough in which to melt some of the best red seal- 

 ing-wax. Cut first a piece of glass about 2 inches 



