COXAL GLAND OF LIMULUS AND OF ARACHNIDA. 
511 
Evidence in favour of the View that the Coxal 
Gland of Limulus and of other Arachnida 
is a Modified Nephridium. 
By 
G. L. Gulland, M.A,, B Sc. 
With Plate XXXVI. 
The following observations were made by the author whilst 
acting as assistant to Professor Lankester in connexion with 
a research on the comparative histology of the vascular , 
system and connective tissues of Arthropoda and Mollusca, in 
aid of which a grant was made by the Government Grant 
Committee of the Royal Society. The specimens of Limulus, 
of various sizes, from a quarter of an inch diameter upwards, 
were very kindly procured for Professor Lankester by Professor 
H. Newell Martin, of Baltimore. 
In a transverse section of a young Limulus of the size repre- 
sented by fig. 3, a at the level of the 4th or 5th appendage 
(such as is represented diagrammatically in fig. 1), the ob- 
server’s eye is at once caught by three or four large spaces lined 
by a peculiar epithelium, in the connective tissue immediately 
external to the entosternite and on the same level with it. 
This is the representative of the coxal gland. As we had a 
complete series of transverse sections of the prosoma, we pro- 
ceeded to reconstruct the gland, by making sketches of the 
spaces at frequent intervals, colouring the drawings so as to 
ensure the recognition of each space through all its changes, 
and from this series of sketches by drawing to a certain scale 
we compounded a diagram which is reproduced in fig. 2. 
