Innocent : A Century's Changes in the Sheffield Flora. 221 
common in Salt’s time and uncommon in ours, for the decrease 
of which there is no apparent reason ; Salvia verbenaca has also 
disappeared from the district ; both these plants have only two 
stamens, unlike the other British labiates, which all possess 
four. 
Temperature has probably increased, and rainfall decreased, 
and our few surviving species of Atlantic type are now only 
found in the valleys away to the West, some of which have a 
rainfall nearly double of that of the City. 
Another group of plants which has disappeared from 
Sheffield, and whose existence here a century ago, 1S as astonish- 
ing as their disappearance, is the psammophilous xerophiles ; 
they are found to-day on the Triassic sands to the East, such 
are :— 
Teesdalia nudicaulis. Ornithopus perpusillus. 
Moenchia erecta. | Vicia lathyrotdes. 
Cerastium semi-decandrum. Potentilla argentea. 
Malva votundifolia. Alchemilla avvensis. 
Trigonella oynithopodioides. Festuca bromoides. 
For the following disappearances I am unable to suggest 
reasons :— 
Malva moschata, Nepeta cataria. 
Evvum tetvaspermum. | Allium vineale. 
Lactuca virosa. Gagea lutea. 
Cichorvium Intybus. 
The subject of species introduced since Salt’s time has not, 
of-course, been dealt with, but such introductions must have 
had some effect on the original inhabitants. 
Some time ago Mr. Sheppard kindly directed my attention 
to an article in the ‘ Bradford Scientific Journal,’ by Mr. Rosse 
Butterfield, on the plant extinctions and decreases in the 
Bradford district. Mr. Butterfield gave a list of 7 plants which 
have been exterminated ; and of 23 which have decreased in 
the Bradford district. Some of them do not occur in the 
Sheffield district, and for others I have no evidence 7, but.as. to 
the rest, 2 of Mr. Butterfield’s extinct species are also extinct 
in this district, and 6 of his decreasing species are extinct with 
us, and 7*of them are also decreasing: there are, therefore, 
the same effects in Bradford as in Sheffield, and in one case 
(Evythraea Centaurium), at any rate, the cause is the same. 
In conclusion, it is unlikely in the case of many of the 
species, that the one cause which I have suggested is alone 
responsible for their disappearance, and probably several ad- 
verse influences have been at work ; it is hardly possible yet 
for us to know why certain species have been defeated in the 
battle of life, but some day it ought to be possible to draw up 
a table of the survival value of plant characters. 
Ig1r Juner. 
