70 Journal of Entomology and Zoology 
The abdominal ganglia are each supplied by two ventral tracheae. The dorsal 
tracheae send vessels throughout the length of the branches on the dorsum of the 
ganglion. Each ganglion is well supplied by numerous small tracheoles. 
The two candal ganglia present some differences in the distribution of tracheal 
elements. The dorsal surfaces of the twenty-third and twenty-fourth ganglia is sup- 
plied by six tracheae. Ventrally there is cne principal branch suppling both by 
numerous tracheoles. 
Histologically the brain and other ganglia resemble mvch those of the more 
generalized insects. I have found little difference in my specimens and those figured 
by Saint-Remy (1890) of S. Morsitans. The cellular masses of all my preparations 
seem much less than those figured by Saint-Remy. The fib@rous area of the brain 
contains some indication of lobular masses. ‘There are at least two sizes of cells 
noticeable. 
In the abdominal ganglia the fibfrous mass occupies rather more than half the 
bulk. The cellular area, composed of several sizes of cells, is closely crowded. 
The caudal ganglia contain less bulk of the fibrous mass and a large area 
of cells. The cells here seem to be all of approximately the same size and type. 
In all preparations, the nuclei appear large, the nucleoli show prominently. 
Tigroid substances was noticed in a few of the larger, better stained cells, especially 
in the brain. Fibrils were seen to enter into certain cells, and touch the nuclei. 
CONCLUSIONS 
1. The central nervous system of S. Folymorpha is compcsed of twenty-four 
generalized ganglia. The brain is less complex than that of the insects. 
2. Of the three primitive elements cf the braia two only are externally apparent. 
3. Tracheae supplying the central nervous system are definitely arranged. 
4. The functional cells of the central nervous system are of several sizes, the 
fib§rous mass makes up the greater bulk of the ganglion. The cellular area is external 
and relatively less abundant. 
5. Nuclei are large, nucleoli are well marked. Fibrils appear to come into 
contact with nuclei. 
BIBLIOGRAPHY 
Case, 8.: General Reactions of a Centipede. 1920 
Journal of Entomology and Zoology. 
Heymonds: 1898 
Zur Entwicklungsgeschichte der Chilopoden. 
Sitzungslier K. press. Akad. Wissenschaft. 
—- — 1901 
Die Entwicklungsgeschiéchte der Scolopender. 
Zoologia, Heft. 33. 
Newport, George: 1843 
Structure, Relations and Development of the Nervous aad Circulatory 
Systems - - - in Myriopoda and Macrourous Arachnida. 
Philos. Transactions of the Royal Society. 
Saint-Remy, G: 1890 
Contributions a l'étude du ceryeau chez les Arthropodes Trachéates. 
Archiv. Zool. Expér. Tome V. suppl. 1887-90. 
(Contribution from the Zoological Laboratory of Pomona College.) 
