124 ^^' ^- ^- Stanley. 



worm tube close under the grass roots, and following it down- 

 wards with the aid of my knife, I came upon what one might 

 term a small " heading" opening from, and at right angles to, 

 the tube. It was scarcely three-quarters of an inch broad, and 

 half an inch high, and so smooth it looked as if it had been 

 formed by the displacement of a pebble. In this cavity, 

 twenty-three inches below the surface, were five Achatinse 

 hybernating. They were all the same size, not quite full 

 grown. As they lay they formed the radii of a circle, the tips 

 of the spires touching, mouth outwards and turned down. 

 The worm tube so close to which they were wintering was an 

 old one, as it was wet and much discoloured with the surface 

 drainage, yet the cavity itself was quite dry. I dug a good 

 way into the face of the cutting, and in one spot, where for a 

 space the size of one's fist the sand was very soft, though two 

 feet below the surface and surrounded with hard sand, I found 

 embedded among the grains more than twenty Achatinae, but 

 all had been dead some time, as the shells were exceedingly 

 brittle. In another worm tube, twenty inches under ground, 

 I took by itself a young Achatina, of two whorls. In all 

 probability this specimen had escaped but a very short time 

 from the egg, 



Achatina acicula occurs abundantly where it occurs, but its 

 minute size and subterranean habits render it rather difficult 

 to find. Instances are recorded of its capture alive on the 

 surface of the ground, but they are very few, and of all our 

 land shells this is the only one of whose life-history nothing is 

 known. 



29. — On some new observations of Vortex Motions, and 

 on the evidence of the possibility of such 

 motions being active in vltal systems. 



By Mr. W. F. Stanley. 



[Read Wednesday, January iSth, 1882]. 



The object of the present paper is to bring before you 

 certain thoughts which sprang up in my mind during my 

 experiments with fluids, of which I have published an account^ 

 a copy of which is in our library. 



Before offering (as I intend to do) some evidences of the 

 possibility of vortex motions being active in vital syste7ns 

 I may briefly discuss two points : — First, the evidence of 

 mechanical action being general in vital systems ; and, 

 secondly, the nature of vortex motions in a general sense. 



If we study the anatomical and functional construction of 



