ON THE OCCURRENCE OF GALLS IN RHODYMENIA PALMATA, 67 
constant association with these outgrowths I am inclined to regard 
it as an animal secretion, stimulating the gall outgrowths. When 
the observations had reached this stage I discov ered the presence in 
the thallus, in one of the diseased tracks, of a nematode worm, 
and I now seemed to have wt an animal a of effecting 
such results, since it recalled at o e the operation e 
Lylenchus Tritici Bast., the so- pre ey cheat eels,” which cause the 
well-known and remarkable disease of wheat owever, it was 
destined to furnish a lesson in the danger of too easily accepting a 
ns 
animal which was distinctly a crustacean. opening up and 
teasing out the contents of some of these channels in the ‘thallus the 
entire animal was exposed in various stages of its rigs Spm only 
one as a rule, however, inhabiting each outgrowt 
of some of the older tracks the animal had evidently burst its way 
out of the thallus and escaped, leaving a hole at the end of a short 
channel in the tissues. These are, of course, entirely disorganised. 
n one instance I found, in the same cavity as the animal, a collec- 
tion of eggs of a yellow ee, ea Oa) than those I had previously 
found, and shaped angularly s to fit into one another, together 
forming a round badp ie more idee a as large as the animal itse 
It occasionally happens that in the plants containing well-deve- 
loped specimens of the crustacean there are no oe while the 
individuals associated with the cael are very young. 
sii 4p ths Hov. T. RB. R. 
which renee further investigation. This investigation he has 
undertaken, and the result cannot fail to be of interest. His sug- 
gestion in a letter to Mr. Murray, that Rhodymenia possibly pro- 
duces galls in response to the stimulus of attack by different 
creatures, seems in these circumstances a very probable one, and at 
all events it will be settled one way or the other by ea further 
research. The figure of Harpacticus chelifer on the Plate is copied 
from Dr. Brady’s Monograph of the Copepoda of the British Islands, 
vol. ii. pl.65. Iam pach indebted to him for his kindness and help 
peat 
for several pees bodies which I have found in parts of the 
thallus where the yellow substance is plen 
I may here mention that, in the British Museum Herbarium, 
similar proliferations and papille to those on the Stonehaven 
preerg were found on a specimen collected in pila 1850, by 
Carroll, at Cork Harbour. Sections of this specimen p 
sented the same appearance also, showing galla in os stages 
