io8 
BRITISH GALLS 
Tylenchus Davainii causes galls on Mosses; usually the 
terminal internodes remain closed, and the bunch of leaves 
forms a terminal artichoke-like gall. Dixon, in 1905, re¬ 
ported its occurrence in Eurhynchium Sivartzi Curnow, and 
also recorded that Thamnium ( Porotrichum ) alopecuvum Linn., 
bears galls caused by an unknown species of Tylenclius. He 
considered that galls of this nature appear to be very un¬ 
common on Mosses—as he rarely came across them among 
the many thousands of specimens that passed through his 
hands in twenty years or more. Mr, W. E. Nicholson, 
however, has informed me quite recently that in his ex¬ 
perience such galls are not very uncommon in this country. 
He kindly sent me some Hypnum cupressiforme gathered 
Fig. 24 —Tylenchus Davainii Bastian. Female. (321.) 
Fig. 25 —Tylenchus Davainii . Male. (32/1.) 
on the Dowms near Lewes which contained eelworms, 
apparently Tylenchus Davainii , in large numbers. The 
galls were terminal, each about 2 mm. long. Nicholson 
thinks there can be little doubt that these galls are 
often overlooked. “ On the Hypnum they might easily be 
passed over. They affect the mosses prejudicially, and 
they are consequently unlikely to be found on specimens 
gathered for herbarium purposes.” He also noted the occur¬ 
rence of Nematode galls on the hepatic Harpanthus scutatus 
received from West Inverness. Schiffner has recorded the 
occurrence of these eelworms on many Mosses on the Con¬ 
tinent. There are also Continental records of hepatics 
attacked by eelworms, presumably this species. 
