SCIENCE-GOSSIP. 



263 



(6) H. RADIATULA, Aider, (hammonis, Strom.) 



jaccetanica, Bgt. Said by Westerlund to 

 belong to H. petronella; subnitidosa, Mouss., 

 is the same. 



viresccns, Esm. 



(7) H. PURA, Alder. 



The names viridula (Manke) Kobelt and 

 lenticular is, Held., appear to belong to our 

 well-known forms. Paulucci has called a 

 form lenticula. 



(8) H. NITIDA, Mull. 



sinistrofsa. Shell sinistral ; see Zool. Record 



for 1879. 

 borealis, Cless; N. Sweden. 

 parisiaca, Mab. ; France, Sweden. 

 machoi, Serv. ; Spain. 



(9) H. EXCAVATA, Bean. 



No varieties recorded from abroad. Wester- 

 lund cites only Schleswig as a locality for 

 the species out of Britain. 



(10) H. CRYSTALLINA, Miill. 



subterranea, Bgt ; France, Germany, Sweden. 



humulicola, Mab. ; France. 



orientalis, Kim. Practically the same as our 



var. complanata. 

 hydatina, Rossm. Larger; aperture a little 



more oblique. 



nitidissima. Baud. 

 subrimata, Reinh. 

 pscudohydatina, Bgt. 

 major. Morel. 



duhnieili, Cless. ; France, Switzerland. A 

 sub- var. of our var. contracta. 



(11) H. FULVA, Miill. 



major, Moq. Much larger. 

 pratensis. Baud. 

 montana, Baud. 



(12) VlTRINA PELLUCIDA, Miill. 



licit. Beck. Norway, Iceland, Greenland. 



A distinct species according to Westerlund. 

 draparnaudi, Moq. ; France. 

 vellaviana, Pascal. 



perforata, West. ; Sweden, Germany, France. 

 sinistrorsa. Shell sinistral. — See Zool. Record 



for 1879. 

 brunnensis, Ulicny. 

 minor, West. Small, depressed, thinner, 



hyaline, aperture rounded. 

 bellardii, Poll. ; Italy. More shining, flatter 



above, more convex below, smoother, 



minutely striatulate at suture. 

 radiata, Amstein. 



{To be continued.) 



EXTINCTION AND NATURALIZATION OF PLANTS. 



A S all the numerous organic creations in the 

 ■^ earth are continually changing, perhaps 

 nothing shows this change better than plants. 

 Nearly every one knows that in an individual 

 plant the tissues and growth are ever changing ; 

 but plants also seem to be moving from place to 

 place, or to locally go out of existence altogether. 



Under these circumstances no one who has 

 made inquiries in this subject will have failed to 

 note how exotic plants gradually establish them- 

 selves in a country, while some become more and 

 more scarce every year till they finally disappear. 

 The foreigners have generally a hard fight before 

 they are classed by botanists as natives ; while the 

 extinct plants still figure in the printed floras long 

 after their total disappearance from the country or 

 county. The printed floras do not therefore 

 always contain trustworthy localities ; and further, 

 they tend to make rare plants disappear more 

 quickly than would be the case if their haunts 

 were kept a little more obscure from the general 

 public. 



Whether rare plants disappear or not generally 

 depends on their attractiveness and beauty, also 

 on their marketable value, when they are eagerly 

 sought for and carried away wholesale by hawkers, 

 etc. These plants, such as primroses, periwinkles, 

 daffodils, wild orchids, snowdrops, lilies-of-the- 

 valley and ferns, are local if not exactly rare, 

 though they are soon made so in some districts by 

 these rogues. Tiilipa silvestrls and some of the wild 

 orchids are occasionally lost by new workings in old 



chalk-pits, and on railway embankments. Others 

 are lost by turning pasture-land into arable fields ; 

 by floods ; the building of railways ; the improve- 

 ment of rivers ; the encroachment of the sea ; the 

 clearing of forests ; the drainage of bogs, etc. 



Exotic plants are introduced into our meadows, 

 woods, etc., by natural or artificial means, also as 

 strays and garden waifs. As agents promoting the 

 first-named we may mention winds, rivers, seas 

 and birds. The second, by intentional naturaliza- 

 tion, many plants having been made at home by 

 this method. The white dead-nettle {Lamium album), 

 which is a very common weed in some parts of 

 England, was once carefully transplanted to Scot- 

 land, and at present some enthusiastic plant-lovers 

 are trying to establish that most beautiful of all 

 our native orchids, the ladies'-slipper [Cypripedium 

 calceolus) in our woods, which were once favoured 

 with its presence. Bulbs, such as snowdrops and 

 daffodils, specially lend themselves to this treat- 

 ment, and a wood planted with hardy-growing 

 subjects forms a quiet and beautiful wild garden. 

 Strays are generally short-lived, but the opposite 

 is occasionally the case. Garden rubbish is thrown 

 into plantations and the bits of plants live for a 

 little time and may even spread. Foreign grasses 

 and weeds are sown in pastures and lawns ; and 

 trees from plantations and arboreta gradually 

 establish and spread themselves, and soon have 

 the appearance of having been wild for years. 



David S. Fish. 

 :2, Fcttcs Row, Edinburgh. 



