500 WALTER: EDWARD COLLINGE. 
The importance of the sensory canal system in fishes has not 
yet been sufliciently estimated, partly, I believe, from the absence 
of any continued and systematic investigations concerning the 
same, and the need of more detailed and reliable information 
upon the development and early stages. The present series of 
papers will endeavour in some measure to meet the first require- 
ment, and may in a few instances add to our knowledge of the 
ontogeny. 
It seems strange, considering the important modifications 
that the skull and cranial nerves have undergone, due very 
largely to the presence of a sensory canal system, and also the 
bearing it has upon the origin of various sensory organs, that 
it has not*hitherto been subjected to a more prolonged and 
thorough examination. So far as I can gather from the 
voluminous literature upon the subject, previous writers, with 
one or two exceptions, have been content to simply describe 
the course of the canals and their branches, omitting any 
account of the innervation or histology, whilst comparisons 
with other species, orders, &c., are almost unknown. 
In pursuing these inquiries I have placed myself under 
many obligations to Professor T. W. Bridge, M.A., of Mason 
College, Birmingham, for his very generous and continued 
assistance and advice; to Dr. Giinther, F.R.S., of the British 
Museum, London, for the facilities which he has at all times 
given me for examining the collections under his care. I take 
this opportunity of expressing my thanks to the Council of the 
Birmingham Philosophical Society for a grant from their 
‘Research Fund’ in aid of these investigations, and to Pro- 
fessor G. B. Howes, Professor J. Cosar Ewart, F.R.S., and Mr. 
Samuel Garman for assistance or advice they have from time 
to time so willingly rendered. 
ii. HisToRIcAL, 
The earliest reference to the system of organs known as 
‘‘muciparous canals,” “sense-organs of the lateral line,” 
“branchial sense-organs,” “lateral canals,’ &c., is the de- 
scription by Stenonis (78) in 1664 of the mucous canals in a 
