30 



The Scottish Naturalist. 



their recesses so great, that one would require, not a month's 

 residence, which was all the time at my disposal, but a year's 

 sojourn in the locality to explore fully its productions. In this 

 sketch I have only attempted to give a general idea of the lichen- 

 flora of Inveraray as it strikes a stranger. And any one who has 

 examined it even as superficially as I have done must be 

 astonished at its immense luxuriance. The large size of the 

 specimens, and their fully developed and fructiferous condition are 

 a sure sign of the purity of the air and the salubrity of the climate- 

 It is a common error to suppose that a vast abundance of lichens 

 indicates an unwholesome district ; since in fact lichens will not 

 grow in a perfect or fruit-bearing condition where the air is impreg- 

 nated with any deleterious substances. In such localities the 

 lichens exist only in a gonidial or rudimentary state, covering trees 

 and walls with a green powder. Judging by this standard we 

 must conclude that Inveraray is exceptionally favourable to human 

 as well as to lichen life. 



THE PERONOSPOREJE OP ORKNEY. 



By Prof. James W. H. Trail. 

 HIS short paper may be regarded as a second supplement 



1 to the " Revision of the Scotch Peronosporese " read be- 

 fore the Cryptogamic Society of Scotland in 1886, published in 

 the Scottish Naturalist in April 1887 (pp. 77-86) with two addi- 

 tional species recorded in January 1888 (p. 208). I spent the 

 whole of the month of August of last year in the Mainland of 

 Orkney ; and of course took advantage of the opportunity to do 

 what I could towards gaining a knowledge of the fungi. In the 

 Mycologia Scotica there is scarcely a record from the Orkney 

 islands ; so that any information was very desirable. The materials 

 obtained will require some time to work out ; but a few of the 

 smaller and more distinctive groups have already been overtaken, 

 among which are the Peronosporece. Of this group I found very 

 few during the first ten days of the month ; but after a few days 

 of rain they began to appear in some plenty. 



