MOTIONS OF INSECTS. 321 



of the sound that it emits before rain, named the Gecko a 

 (Lacerta Gecko) could walk against gravity up the walls 

 of houses ; and comparing this with the parallel mo- 

 tions of flies, he was desirous of having the subject more 

 scientifically illustrated than it had been. This inquiry 

 was put into the able hands of Sir Everard Home, so 

 justly celebrated as a comparative anatomist, who was 

 assisted in it by the incomparable pencil of Mr. Bauer : 

 and it has been proved most satisfactorily, that it is by 

 producing a vacuum between certain organs destined for 

 that purpose and the plane of position, sufficient to 

 cause atmospheric pressure upon their exterior surface, 

 that the animals in question are enabled to walk up a 

 polished perpendicular, like the glass in our windows 

 and the chunam walls in India, or with their" backs 

 downward on a ceiling, without being brought to the 

 ground by the weight of their bodies. 



a Amcen. Acad. i. 549. The Gecko, probably, is not the only 

 lizard that walks against gravity. St. Pierre mentions one not 

 longer than a finger, that, in the Isle of France, climbs along the 

 walls, and even up the glass after the flies and other insects, for 

 which it watches with great patience. These lizards are sometimes 

 so tame that they will feed out of the hand. Voyage, &c. 73. 

 Major Moor and Captain Green observed similar lizards in India, 

 that ran up the walls and over the ceilings after the mosquitos. 

 Hasselquist says that the Gecko is very frequent at Cairo, both in 

 the houses and without them, and that it exhales a very deleterious 

 poison from the lobuli between the toes. He saw two women and a 

 girl at the point of death, merely from eating a cheese on which it 

 had dropped its venom. One ran over the hand of a man, who 

 endeavoured to catch it ; and immediately little pustules, resembling 

 those occasioned by the stinging-nettle, rose all over the parts the 

 creature had touched. Voyage, 220. M. Savigny, however, who 

 examined this animal in Egypt, assures me that this account of 

 Hasselquist's, as far as it relates to the venom of the Gecko, is not 

 correct. 



VOL. JI. Y 



