The Scottish Naturalist. 213 



would undoubtedly restrict the virulence of the disease ; but this 

 is not properly to cure it, but to give way before it by withdraw- 

 ing the crop and foregoing the profits to be derived from it. 

 Experiment shows that the disease is not a mere result of 

 peculiar modes of tillage, or of characteristics of the season, 

 though these may promote or retard its growth, but that it is a 

 plant, one crop of which arises from the seeds of a previous 

 crop. Probably under existing systems of rotation, wherever the 

 club-root fungus has got a firm hold, extermination is impossible. 

 Other questions then arise not belonging to the purpose of our 

 meeting. Who knows whether it may not be good for agriculture 

 that such fungi as those which partially destroy the potato and 

 turnip crops cannot be exterminated ? Thanks are undoubtedly 

 due in certain parts of our country to the Peronospora infestans, 

 for destroying a means of subsistence which was over-abundant 

 without enterprise and energy, and left the better resources of 

 the cultivators to waste themselves in idleness. And who knows 

 but the prevalence of Plasmodiophora bi-assicce may divert the 

 course of agriculture into a new and more fertile direction ? 



North Kinmundy, Aberdeen, September 1879. 



SCOTTISH GALLS. 



By J. W. H. TRAIL, M.A., M.D., F.L.S. 



SINCE my last contributions to this subject in the * Scottish 

 Naturalist ' (vol. iv.), I have met with a few kinds of galls 

 not previously found by myself in Scotland, though one or two of 

 them have already been recorded by others. The past season 

 seems to have been very unproductive in galls, as far as my 

 observations in the district around Aberdeen go, though a few 

 common species were very abundant. 



Cakile maritima, L. — On the root of a plant of this species, 

 gathered near the mouth of the Don in July, were several galls 

 like those so common on cabbages — i.e., hemispherical swellings 

 about ^ inch in diameter, each inclosing a rather small cavity in 

 which lay a white larva of a beetle, probably Ceiithorhynchus sp. 

 Unfortunately, no more galls could be found, though search was 

 frequently made subsequently, hence I was unable to rear the 

 maker of the gall. 



Stellaria holostea, L. — I formerly (' Scot. Nat.,' iv. 13) noted 

 the occurrence on this plant of false galls, the work of Aphides, 



