ON THE NERVOUS SYSTEM OF THE NEMATODA. 197 
Ameebze in general in quite a new light, assimilating them 
more closely to other non-Rhizopodal genera, such as Tha- 
lassicolla, Acanthometra, &c., and placing them, in Dr. 
Wallich’s opinion, at the head of the Rhizopoda. 
On the Nervous System of the Nematoda. 
Tue nervous system of the Nematoda forms the subject of 
an interesting paper by Dr. Anton Schneider,* whose pre- 
vious contributions have contributed so largely to our 
knowledge of the anatomy of that class of worms. His 
first paper, “On the Lateral Lines and Vascular System 
of the Nematoda,” appeared in 1858,+ and has been followed 
by two others in 1860—‘“‘ On the Muscles and Nerves of the 
Nematoda,” { and “ Remarks on Mermis.” § In his present 
communication he continues his observations on the nervous 
system, of which we proceed to give a brief abstract. 
A nervous system was described, in 1816, by Otto, in 
Strongylus gigas, but the first important contribution on the 
subject was by Meissner, in 1858-55, who described what he 
regarded as a complete system of nerves in Mermis albicans 
and nigrescens. This was followed up by Wedl and Walter 
in a detailed account of the same system in another species. 
But the supposed nerves of these authors were shown by Dr. 
Schneider in the latter two papers above cited to belong to the 
muscular system; and his views have since been adopted by 
Leydig. || 
Even with respect to the central nervous system, Meissner’s 
views were entirely upset, what he regarded as such having 
proved to be the esophagus. Dr. Schneider was unable also 
to confirm Walter’s description of the central nervous system 
in Oxyuris ernata. The true constitution, therefore, of the 
nervous system in the Nematoda remained in considerable un- 
certainty. The only central organ that appeared likely to be 
such was a pale band lying on the cescphagus, first noticed 
by Lieberkuhn, Wedl, and himself. 
Since that period, Dr. Schneider has kept the subject in 
constant view, and believes that he is now in a condition 
fully to describe both the central and peripheral nervous 
systems in the Nematoda. He attributes the success he has 
* € Archiv Anat., 1863, p. 1. + Ibid. 1858, p. 426. 
t Ibid., 1860, p. 224. § Ibid., 1860, p. 243. || Ibid., 1861, p. 605, 
