150 THE ZOOLOGIST. 



it is shortened behind to the same extent. The effect of this is that a kind 

 of sliding motion is produced. This motion is materially assisted by the 

 intercalation of a layer of mucus between the foot and the object on which 

 the animal crawls. The fugitive snail's course can always easily be tracked 

 by the marks of slime left behind. Why should it leave this slime 

 behind? Because the skin of the snail is so exceedingly sensitive, that 

 the contact with a rough surface is apparently very repugnant to its 

 tender feelings. It therefore provides itself with an abundant supply 

 of mucus, which in the case of Helix aspersa is furnished especially by the 

 large foot-gland, hut to a minor extent also by the mucous glands. 

 However, although this mode of locomotion may seem very pleasant, being 

 at any rate quite unique among animals, the snail's lot is not a happy one. 

 When the locomotary muscles are once set a-going, the movement is 

 automatic, that is to say the snail can neither increase nor slacken its 

 pace, nor can it go backwards. In that respect it is like a watch which 

 may be wound up and which we can stop at will, but we cannot force the 

 wheels to change their rate of velocity. Hence when the snail is pursued 

 by an enemy, it is unable to run away or rather slide away. The only 

 possible manner to evade the enemy is to stop the motion of the foot and 

 wind up another series of muscles by means of which the snail is enabled 

 to retire within its shell. — Robert F. Sohauff (Museum of Science and 

 Art, Dublin). — From, ' The Journal of Couckolof/y,' October, 1887. 



SCIENTIFIC SOCIETIES. 



Linnean Society of London. 



March 1, 188S. — W. Carruthehs, F.R..S., President, in the chair. 



On a ballot being taken, the following were elected Fellows of the 

 Society: — Messrs. J. T. Baker, J. 13. Farmer, H. P. Greenwood, J. F. 

 Maiden, A. G. Renshaw, A. E. Shipley, and J. A. Voelcker. 



An interesting collection of Ferns from the Yosemite Valley was 

 exhibited by Mr. W. Ransom, who also showed some admirable photographs 

 of rare plants, taken in America, many of them of the natural size. 



Mr. J. E. Harting exhibited a coloured drawing, life-size, of a South 

 American game-bird (the Rufous Tinamu) which has been successfully 

 introduced into this country at Brightlingsea, Essex, by Mr. J. Bateman, 

 and made some remarks on its affinities, peculiarities of structure, and 

 habits. In a discussion which followed, Prof. Mivart, Mr. Christy, and 

 Mr. W. H. Hudson took part, the last named giving some account of the 

 bird from personal observation of its habits in the Argentine Republic. 



