CHAPTER OF VARIETIES. 237 



generally become of a paler hue, and finally pure white. White- 

 flowered varieties of plants, as Scabiosa, succisa, Thymus Serpyllun^ 

 Prunella vulgaris, Pedicularis sylvatica, &c., I have also most com- 

 monly found in damp and watery places, so that, in these cases, 

 it is evident a superabundance of moisture effected the change of 

 colour, either by absorbing or decomposing the colouring principle ; or 

 perhaps, more correctly speaking, by the transposition of the molecules 

 of those fluids, which, by their different refraction of the rays of light, 

 give rise to the different colours of flowers. In drying specimens of 

 plants for my herbarium, I have likewise observed several peculiar 

 changes of colour take place, as, for instance, the snowy white blos- 

 soms of Asperula odorata, became black; the yellow flowers of Pri- 

 mula, green ; and the green leaves of Mercurialis perennis, blue. I 

 heartily wish that some able chemist, who has leisure, would turn his 

 attention to the subject of vegetable colours, and give it a thorough 

 investigation. WILLIAM GARDINER, JUN. 

 Dundee, April 5, 1833. 



ON THE CHURCH-YARD BEETLE. W. J. T.'s communication in 

 your Number for March, on the " Moulting of the Cock-roach," brings 

 to my recollection a similar case as regards the white appearance of 

 the insect. 



About two years ago, I caused a bin in my wine-cellar to be cleared 

 of some dirty and decayed saw dust, among which I discovered a num- 

 ber of grubs of a dirty yellow colour, highly polished, varying in length 

 from half an inch to an inch and a half. I placed a few of them with 

 some of the dust in a bottle, such as is used for preserving gooseberries, 

 when they instantly buried themselves, which they repeated as often 

 as they were exposed to the light. 



Being my own butler, I occasionally examined my prisoners, but 

 found no change till after several months, when I at length found two 

 or three had assumed a distant resemblance to a beetle, nearly shape- 

 less, but perfectly white ! After several weeks they became what I 

 considered the church-yard beetle, (Blaps Mortisaga), though as yet 

 of a dirty semi-transparent grey ; they at length became of the tru e 

 Warren s jet, as your correspondent says ; one of them I added to my 

 small collection. G. W. B. 



ON FLIES WALKING AGAINST GRAVITY. I have an idea that 

 neither Sir Everard Home's comparison of the foot to a sucker, nor the 

 allegation of Dr. Power as to the flies glueing and soldering their feet 



