458 
PROFESSOR J. STEPHENSON AND DR BAINI PRASHAD ON 
in the gland-cells that could be put down to the difference of treatment. In none of 
the specimens examined, with the exception of the Lumbricus, were there any such 
accumulations of calcareous particles as to interfere with section-cutting ; we have 
thus been spared a source of trouble which has been felt by some previous workers. 
The Ocnerodrilus were fixed whole in Zenker’s fluid. The Octochsetus, which 
came from the collection of the Indian Museum, was not specially fixed for histo- 
logical work, but we have no reason to complain of the results of fixation as shown 
in the actual sections ; we have, however, been careful not to describe the histological 
appearances in greater detail than is warranted. 
We have to thank Professor Youngman for the careful preparation and fixation 
of the specimens of Eutyphceus. Some worms that he sent us to Lahore alive were 
unfortunately dead or not in a suitable condition on their arrival, and he kindly 
then sent us a number of specimens opened under salt solution and fixed in formalin ; 
others were fixed in sublimate-acetic ; the alimentary canal had been freed of 
extraneous matter by feeding for twenty -four hours on damp blotting-paper, or by 
syringing out at the time of opening of the worm. Our thanks are also due to Dr 
Ashworth for a similar careful fixation of the specimens of Lumbricus. 
The two staining methods that we have principally employed have been Dela- 
field’s haematoxylin followed by eosin as a counter-stain, and Dobell’s modification 
of Heidenhain’s iron-hsematoxylin. 
The Alimentary Blood Sinus. 
A true conception of the morphology of the calciferous glands depends in the 
first place on an accurate apprehension of the relations of the vascular channels in 
the alimentary wall. The subject was exhaustively discussed, on the basis of the 
results obtained up to that date by the numerous investigators who had, specially or 
incidentally, worked at the problem, by Lang (14) — it occupies indeed a fundamental 
place in his Trophocoltheorie — and has since that time engaged - the attention of a 
number of his school, as well as of Vejdovsky. 
The vascular layer of the alimentary wall in the Annelida, which intervenes 
between the epithelium and the muscular coats, consists not of definite blood-vessels, 
but is of the nature of a sinus — rarely continuous all round the gut, mostly divided 
up into a number of anastomosing channels by adhesions between the epithelial layer 
on the one. side and the muscular coat on the other ; the usual condition is that of a 
copious network. According to Lang and his followers, this network has no proper 
walls ; the blood bathes the epithelial cells on the one hand and the muscular fibres 
on the other. That flattened nuclei, of unknown origin, are to be seen in many cases 
on the walls of the sinus is undeniable ; but they do not form an endothelial lining, 
and the peri-intestinal sinus, or network, remains essentially a space between the 
epithelium and the muscular layer. 
