54 
short branches at the lower internodes, become considerably en- 
larged, and each galled bud may reach as much as 3cm. in length 
by 4-6mm. in breadth; usually several such enlarged buds arise 
side by side, so that the whole mass may exceed 3cm. in 
diameter. The bases of the leaves are much widened, and over- 
lap one another, enclosing spaces tenanted by the insects. The 
leaves remain abortive beyond the sheath frequently. These 
growths are not rare in suitable localities throughout the country. 
(VI., 257.) 
AGROSTIS ALBA L.:— 
On this grass galls are often found to occur in a locality on the 
coast south from Aberdeen, in autumn. They are situated in the 
leaf-blade close to where it joins the leaf sheath usually ; less often. 
they are found scattered over the blade, but do not exceed two or 
three in a leaf. They are oval or linear dull red-purple swellings: 
about 2-5 by I-2mm.; and in the interior contain an irregular 
closed cavity, formed, as it seems, by the separation of the cells 
at that part. In the space so formed live a number of Anguillulae 
belonging to the genus Zylenchus Bastian. Similar galls have 
. been described from Germany on A. canina and on Festuca ovina 
(VI, 17-18.) 
ELYMUS ARENARIUS L. :— 
Has swellings on the finer rootlets, often close to the tip as nearly 
round bodies, }-13mm. in diameter, or less often forming spindle- 
shaped swellings, which may be 3 by 2mm. in size. The healthy 
rootlets do not exceed 1mm. in diameter, hence the galls are 
readily distinguished, though of the same pale colour as the roots.. 
On section the gall is found to be chiefly made up of an enlarge-- 
ment of the cellular tissue. In the interior of the gall live the 
makers, belonging, like those on A. alba, to the genus Zylenchus.. 
not, as suggested by Karl Muller of Berlin, in 1883, (“neue 
Helminthocecidien,” p. 12), tothe genus Heterodera Schmidt. I 
have examined the mature female, whichis a true Zylenchus, 
Common on sandy beach near Aberdeen. (VZ, 78-79.) 
The following corrections or remarks fall to be made as an 
appendix to my former paper (1878). They are largely due to in- 
formation kindly communicated to me by Dr. Franz Loew, of 
Vienna, and such corrections are indicated by (F.L.):— 
Hypericum Putcurum L. The gall (57) appears to be the work 
of Cecidomyia Hyperici Bremi, and not of C. serotina 
Wina (F.L.). 
