
568 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
swelling of the nerve was usually seen ; this is possibly an arti- 
fact. In a few cases nerves were traced perhaps one-half the 
length of the cavity. In these cases there was a swelling of 
the nerve just before its apparent termination (Fig. 7). 
I found no evidence to indicate nerves ending in gland cells 
or trichogen cells by such branches as have been described and 
figured by Blanc (90) but in every case the very fine nerve 
termination could be traced up past the hypodermal cell layer 
with no branches. 
SUBHYPODERMAL NERVE PLEXUS. 
Villanes (81), in insects, figures a subhypodermal nerve 
plexus made up of multipolar nerve cells. In '93 Rina Monti, 
also working on insects, described a similar plexus, and in '95 
Bethe described similar structures in Crustacea. Nemec (96), 
in isopods, and Holmgren ('96), in a sphinx-moth larva, show 
multipolar networks of subhypodermal cells. All the work 
thus far was by means of methylen blue or ordinary methods, 
and because of the apparent antagonism with the neuron theory 
much attention was directed to this subepithelial plexus, and 
doubts were raised as to the nervous nature of these cells. 
In 1898 Schreiber, who had already in 1897 together with Nus- 
baum published a paper on the peripheral nervous system of 
Crustacea showing these multipolar cell plexuses, published 
another short paper showing these cells demonstrated by means 
of a modified Golgi method, and at the close of his article 
draws the following conclusions : 
I. An identical methylen blue staining of the subepithelial multi- and 
bi-polar nerve cells. 
2. Like staining of both forms of cells by the Golgi method. 
3. True connections of the nerve cells with nerves. 
A few months later Holmgren confirms, on the whole, 
Schreiber's results, but speaks of many-branched subhypo- 
dermal cells, as described by Bethe in Crustacea, and probably 
confused by Nusbaum, Schreiber, and other writers on Crus- 
tacea with multipolar nerve cells. Holmgren distinguishes 

