2 72 ARA CHNOIDEA. 



CASE parency permitted him to study the life of his httle captives under 

 the microscope. The females laid eggs (regularly oval) from the 

 very commencement. The eggs hatched in ten or fifteen days, 

 splitting longitudinally. When the young mite came out, it was 

 hexapod. They cast their skin several times, and it is after the 

 first or second change that they get their additional pair of legs. 

 The skin splits behind, and they come out of the old skin 

 creeping backwards. It is usually considered that they are 

 mature and full-grown when they have got eight legs ; but in 

 speaking of other mites we have already explained that this is 

 only partially true. They cannot be called adult until they are 

 provided with complete sexual organs, and this does not take 

 place until later. At first no sexual distinction is visible. 



This is the species that gave rise to a good deal of talk among 

 scientific people some forty years ago, as having been supposed to 

 be produced by electricity. It may be remembered that in the 

 beginning of the present century, there was a sort of vague idea in 

 the scientific or semi-scientific world in favour of electricity being 

 the source of many of the phenomena of life. The limits and 

 extent of its power were of course even less known than at present, 

 and all sorts of wild experiments were tried in the search after 

 truth. One gentleman set up lines of electrical wires over 

 portions of his estate, with the view of ascertaining whether the 

 plants would not thrive better under what he supposed would be an 

 increased flow of electricity. Others tried similar experiments in 

 different directions, and among them two gentlemen, Messrs. Cross 

 and Weekes, set themselves to ascertain whether by the conthmous 

 use of electrical apparatus they could not produce organic beings, 

 either plants or animals. Mr. Cross's process was to operate on 

 volcanic stone kept moist by a weak solution of silicate of potash, 

 super-saturated with muriatic acid, constantly subjected to elec- 

 tricity. After carrying on this for a time, he at last found some 

 mites wandering about his apparatus or chemical solutions, and ar- 

 rived at the conclusion that they had been produced by his electrical 



