INFLUENCE OF LATERAL-LINE CANALS 329 
HISTOLOGY OF THE CANALS AND ASSOCIATED BONES 
Kindred (719) has discussed in such a satisfactory manner the 
histological relations of the lateral-line canals and associated 
bones in the early stages of Amiurus that little in addition need 
be given here. His figures are, however, for the most part dia- 
grammatic and fail to show the very intimate relation existing 
between the spicules of bone, especially in advanced stages, 
Fig. 5 Photomicrograph of a lateral-line sense organ in its enclosed canal 
from the body of Amiurus. 450. This figure shows especially well how far 
removed and how isolated the sense organs are from the center of osteogenesis 
which is found on the periphery of the canal (c. ¢.) itself. c., lumen of the canal. 
c. t., dense connective tissue protecting the contents of the canal and on the 
surface of which bone deposition begins. — s. 0., lateral-line sense organ. 
fitting very closely to the dense connective-tissue canal with its 
epithelial lining and mucus cells. In some places the bone 
seems actually to replace the wall of the canal, as would be ex- 
pected in the growth of the skull bones. In every phase of their 
histological structure the canals and the bones bear out the re- 
lationship already given. I have not thought fit to follow out 
the histogenesis of the bone in detail or to try to solve the prob- 
lem of the highly osteoid nature of fish bone. That phase has 
little bearing on my problem. Wright (’84, p. 263) has likewise 
discussed the histological relations of the canals. 
