S30 
HERBERT P. CARPENTER. 
surface of the two former groups. His theory reminds one 
of Kowalevsky^s celebrated attempt to prove that the brain 
of a worm represents the hinder end of the Vertebrate spinal 
cord; and one cannot help feeling that, despite the un- 
doubted value of his observations, some (though by no 
means all) of the conclusions which he has based upon them 
will not bear a close investigation when compared with 
the primary facts of Echinoderm structure. 
