CORRESPONDENCE. 93 



mirror usually occupies. This lie strongly illuminates ; then, by using as 

 a condenser the power in his possession next lower to that he wishes to 

 test, an image is formed, at the level of the stage, of the selected object, 

 but extremely minute. Upon this reduced image he brings to bear the 

 object glass he is testing. This enlarges the image, and enaoles him to 

 compare it in all its details with the test object, which is of a size he 

 can measure with his naked eye. If the result is satisfactory, he can 

 use the objective, thus tested on the known, with confidence upon tho 

 unknown. I applied this test most easily to several powers, of which 

 the highest was a Ross l-12th, with satisfactory results. A l-5th of 

 Swift's, very moderate in price, compared very favourably with some 

 much more expensive powers. The object used was a piece of printed 

 paper, cut round so as to lie flat on the face of the mirror. — Edmund 

 Tonks. 



Subterranean Fungi, &c. — A wish is expressed in the February number 

 of the " Midland Naturalist " for information respecting the subterranean 

 and light-avoiding Cryptogamic plants, occurring in the Midland 

 District. Though I have not made the subject a special study, I may 

 mention instances of the occurrence of such plants. Rhizomorpha 

 medullar is exists creeping down to a great extent on the walls of a 

 covered well, near my residence. I have also seen the same 

 curious plant descending on the walls of a friend's wine cellar. This 

 plant was fully described and figured many years since in the Linnean 

 Transactions. A plant, possibly an Alga, but with crowded branches, 

 only an inch or two long, and a line wide, compressed, of an orange 

 colour, and more divided below, occurs dependent from the woodwork 

 covering wells, and also from the roofs of vaults. Racodium cellare, or 

 mouseskin byssus is, of course, a common find in our cellars ; and I have 

 had it sent to me from the cellar of one of our Universities, noted, 

 however, for better productions. A friend tells me that he found 

 immense masses of a similar plant, composed of a white or reddish 

 thready structure, in a mine on the Great Orrne's Head. The Pry-rot 

 (Merulius) is, unfortunately, too well known. It has, to my knowledge, 

 destroyed the wooden flooring beneath the pews of a large church, and 

 also the staircase in a friend's mansion. Subterranean fungi also occur 

 very frequently in coal mines. I noticed some timber that was 

 phosphorescent owing to the presence of the hymenium of a fungus ; and 

 the same appearance occurs in hot weather at the decayed foot of posts, 

 &c. — E. G., Stoke-upon-Trent. 



Natural History Notes. — The winter has been felt very severely 

 at Oscott, more so than for many years. The hard frosts have killed 

 many of the evergreen shrubs in the plantations. The Arbutus, 

 Laurestine, Portugal Laurel, and Bay, have nearly all succumbed to the 

 severity of the season ; and even the common Laurel, generally so very 

 hardy, has suffered considerably. The spring, too, is unusually late, much 

 later here than in the neighbourhood. The following are the observations 

 recorded by the Oscott Natural History Society : — February 22nd. — 

 Snowdrop, Daisy, and Chickweed in flower. 27th. — Redwings flocking 

 together, starting northwards; Skylark, Chaffinch, and Song Thrush 

 singing. 28th. — Daphne Mezereon in flower. 29th. — Coltsfoot and 

 Hellebore in flower. March 2nd. — Ants working. 3rd. — Elder tree in 

 leaf. 5th. — Several Ladybirds seen. 6th. — Crocus in flower, and House 

 Flies seen. 7th. — Hawthorn in leaf in sheltered places. 10th. — Ground- 

 sel and Polyanthus in flower ; Cockchafer and Wasp seen. 11th. — Bertius 

 aquifolia and Yew in flower. 12th. — Ranunculus Lenormandi. 14th. — 

 Ceraetium viscosum and Scleranthui annum in flower. 17th. — HorBB CheBt- 



