AMPHIOXUS LANCEOLATUS. 
391 
(15). It is not my immediate purpose to discuss the histology 
of the notochord of Amphioxus, but to determine the existence 
of natural spaces within that animal which have to be dis- 
tinguished from artifact spaces. The two intrachordal canals 
are connected with the most violent distortions of the shape 
of the notochord under the influence of reagents. The greater 
or less rapidity with which osmotic currents are established 
and the alternative distension or shrinking of the canals leads 
to such alterations in the shape of the notochord as those 
shown in outline in PI. XXXVI j3, fig. 10, a, b , c, d. 
The sudden and powerful contraction of the muscles 
attached to the connective-tissue sheath of the notochord, and 
to the connective-tissue septa passing from it, also helps in the 
distortion of the notochord. The extent of the distortion 
caused by the contraction of the muscular fibres of the myo- 
tomes, may be judged of by the large spaces which are fre- 
quently left where they have torn themselves away from the 
connective tissue. The undoubtedly artifact spaces thus 
produced must be distinguished from the remarkable spaces 
between myotomes and notochordal sheath, and again between 
myotomes and neural skeleton, which have been described by 
Schneider, and are related to the roots of the anterior and 
posterior spinal nerves. 
In view of the undeniable distortions of the notochord 
which the muscular strains and the distension or shrinking of 
the intrachordal canals must produce, I feel great hesitation 
in admitting as natural structures the remarkable apparent 
perforations of the sheath of the notochord, found dorsally on 
either side of the dorsal intrachordal canal at regular inter- 
vals ; and according to Moreau, who first described them under 
the name “ godets,” placing the dorsal intrachordal canal in 
communication with the neural canal, within which the nerve- 
cord is contained. 
I am inclined to consider the “ godets ” of Moreau as 
naturally existing tubercles of the notochordal tissue, as shown 
in PI. XXXVI A, fig. If. But it appears to me that they do 
not completely perforate the sheath of the notochord, nor 
