Reviews and Records in Anatomy and Physiology. 111 
not seen by others who had searched carefully for it, we suggested 
that this direct connection, when present, might be an exceptional 
condition. But numerous researches since published, and espe- 
cially the very complete memoir of Axmann,* represent this as a, 
very common form of disposition of the elements of nervous cen- 
tres in man and the mammalia. The subject is indeed somewhat 
that this last gradually disappears and the nerve appears as a 
homogenous cord. But from our own investigations upon the 
terminal nerves of some insects, we stispect that this disappear- 
ance of the true fibrillee may have been apparent and not real; 
for we have, in the cases referred to, thought that the like was 
true, but using higher powers with some reagents, the fibrille 
Were seen. We think therefore that whatever may be made of 
termination of the nerve-fibre, the fibrilla structure is never lost. 
Digestive Apparatus.—This structure, according to Meissner, 
presents so mauy peculiarities and is so widely different from any 
thing observed in other animals, that we almost relinquish any 
attempt to give even a brief description of it, without the aid of 
figtires. In the first place, the alimentary canal has no anal or 
€xcretory passages, and therefore the food and assimilation must 
be such as to leave little or no so-called faecal matter. 
_“tom the circular buccal orifice proceeds a semi-canal a short 
distance, when it passes into another structure. This semi-canal 
1s the esophagus. ‘The structure into which it passes is a tube 
quite small at first but which soon expands and is filled with a 
finely granular spongy-like substance, and is alternately dilated 
from side to side into sacs. Through this laterally varicose tube 
the semi-canal of an cesophagus extends to its very end. Sup- 
pose then a tube with alternate lateral dilatations, filled with a 
tube like an cesophageal groove. Each of these dilatations has an 
‘vetsion—a folding in of its internal membrane, producing an 
tion, which is continuous into a tube connecting with some adi- 
Pose receptacles. 
: Axmann, Beitr, z. mikroskop. Anat. u. Phys. d. Ganglien-Nervensystems des 
Menschen wu, d Wirbelthiere. Berlin, 1853. 
