microcephalous new-born pig, etc. 
451 
notice that in absolute size, no appreciable difference obtains. 
And yet the cord of the abnormal specimen can receive no contri- 
bution from the cerebrum, since the latter did not exist. This 
observation seems to support the view that the pyramidal tracts 
of the cord are laid down in situ and owe nothing to fibres descend- 
ing from the cerebrum. Moreover “Weigert” preparations reveal 
the presence of medullated fibres in those tracts. 
After the central nervous system had been thus examined, 
the neck was dissected. The general appearances are shewn in 
Fig. 17, which represents the dissection on the right side. The 
globular cranium gave attachment to a mass of nuchal muscles, 
and to the sterno-mastoid muscles. Anteriorly, the skull was quite 
imperforate and at this stage not the smallest trace of maxillae or 
mandible was perceptible. The hyoid bone and thyroid cartilage 
were quite distinct, however, and the hyoid bone was found to be 
suspended from the sides of the cranium by two symmetrical 
muscles (which are certainly not the Mm. stylo-hyoidei). Be- 
tween these a mass of soft tissues closed in the pharynx. 
VOL. xiv. pt. v. 
30 
