KEW : ON THE MUCL'S-TURKADS UF LAND-SLUGS. 



95 



7. Ferussac. Histoire Naturelle generale et particulieredes Mol- 

 lusques terrestres et fluvialiles, 1819, p. 34-6, 73-4- 



Ferussac chiefly observed Agriolimax agrestis of which he figures a 

 suspended individual (fig. 2). He is the first to regard the thread as 

 a continuation of the slime-trail of ordinary progression: 



Les espt-ces que nous avons examinees se 

 laissent tomber sans la moindre hesitation, lorsqu' 

 c-Ues veulent airiver a un plan inferieur. Ellcs 

 atlachent aux corps qu' clles quittent, X e\- 

 irtmite (T un fil, ou mieux de la lame muqueuse 

 (|u' elles laissent habiluellement sue les suiTaces, 

 ct qui est transsudee par les pores du plan loco- 

 nioteur; cette pelile lame se continue en un fil 

 [jlat el triangulaire de la forme de la partie ter- 

 minale de ce plan. Mais bientot ce fil change 

 de forme par suite des efforts combines que fait 

 cet animal, et qui tendent a le tirer, a 1' arrondir, 

 en meme temps que les cotes du plan locomoteur 

 se contractent sur le veritable pied, qui par un 

 mouvement d' ondulation amene vers sa pointe, 

 oil se file le petit cable, toute la matiere muqueuse 

 que la contraction laterale pent produire. 



8. Bree, W. T. Spinning Slugs, Lou- 



dotis Mag. Nat. Hist.., vol. 2, 1S29, 

 p. 69. 



I have before me ... a slug 

 which I discovered suspended by the tail from 

 the leaves of a tree for the space of about a fool 

 (ir more. ... I have several times met 

 with these spinning slugs suspended Ijy iheir 

 threads. 



9. M. Spinning Slugs, Tom cit., p. 303. 



On very many occasions have I observed the descent of the connnon 

 grey and common green-bellied slug [sic] from trees and bushes, .... any 

 small snail [slug], in good health, can let itself down from almost any height to the 

 ground, by the tenacity of the slime exuded retromissively from the pores of the belly. 

 The same muscular motion of the belly, exerted on giving motion to this footless 

 animal on the ground ... is also exercised in the air ; adding thereby to the 

 length of the suspending line till they reach the ground. 



10. Bouchard-Chantereaux. Catalogue des Mollusques terrestres 

 et fluviatiles observes jusqu'a ce jour a F etat vivant dans le 

 D(5partement du Pas-de-Calais, Mem. Soc. d' Agric, cy-'c.,Bon/ognc- 

 siir-Mer {2\ vol. i, 1837, p. 166. 



The author several times saw young L. arbonim descend from one 

 branch of a tree to another. The creatures, with the posterior part of 

 the foot fixed to the branch they wished to leave, were seen 

 stretching out the anterior parts as if seeking for a support; and not 

 finding one they commenced a descent, during which the foot 



Fig. 2. 



After FiJrussac. Hist. Nat, gcii. 

 et; part. IMolkisques terr. et fluv., 

 1819, pi. 5. fig. 9. 



