632 DR. H. CHAELTON BASTIAK OX THE ANATOMY AND PHYSIOLOGY 



Fig. G. Section of same through latere- ventral cavidal pores : — «, chitinous portion of 

 integument ; h, clccp cellulo-glandular portion forming a pretty thick uniform 

 layer; c, c, caudal pores. 



Fig. 7. Section of male Ascaris megalocepliala a short distance above ano-genital cleft ; 

 references same as in Plate XXIII. fig. 4. Principal differences to be noted 

 are the presence of two equal male spicules in strong sheaths, the greater 

 thickness of the longitudinal muscle-bands, and the double row of ventral 

 papilla) on each side. 



Fig. 8. A large tripolar ganglion-cell seen in substance of left lateral band, anterior to 

 oesophageal ring. 



Fig. 9. Exit-tube and arch of excretory vessels with the large granular cell in a thick- 

 ening of the walls of the left branch; the lumen in this situation is also 

 narrowed, and is often somewhat variable in size in other parts of the vessels. 



Fig. 10. Diagrammatic representation of the arrangement and distribution of the trans- 

 verse vessels cdntained in the deep cellular layer of a medium-sized Ascaris 

 megalocepliala, the body having been slit up in the mid-dorsal region, and the 

 viscera with great longitudinal muscles removed : — a, right, and a\ left lateral 

 band ; h, ventral median line ; c, ventral excretory pore ; d, \vl\a ; e, anal 

 cleft. 



Fig. 11. Portion of integument of same more highly magnified, showing a pair of trans- 

 verse vessels, which do not cross one another : — a, right lateral band ; b, its 

 contained vessel ; c, c, median lines ; d, d, thickenings of deep portion of 

 integument on either side of lateral band; e, e, transverse vessels, Avhich 

 magnified to this extent, appear to be simple lacunar channels running 

 through the substance of cellulo-granular layer in an undulating manner. 



Fig. 12. Portion of one of these vessels isolated, and more highly magnified ; its walls 

 showing longitudinal fibres and a few intermixed granules. 



Fig. 13. Section of muscle-cells and integument of Ascaris megalocejjhala : — a, chitinous 

 portion of integument; b, cellulo-granular layer; c, fibrous aponeurosis 

 bounding same ; d, contractile portion of muscle-cell ; d', contained medullary 

 granular matter ; e'-e^, sections through different portions of muscle-cells, from 

 narrow closed extremities to wide median portions, from which the transverse 

 prolongations (/, /) are given off. 



*Fig. 14. Transverse section of Dracunculus medinensis : — «, chitinous portion of integu- 

 ment ; b, deep cellulo-granular layer not presenting the usual lateral bands, 

 though the muscular interspaces are unusually wide; c, bounding wall of 

 greatly developed uterine sac ; d, compressed intestine ; e, e, space occupied 

 by dorsal muscles ; ef, e', ditto by ventral. 



*Fig. 15. Glandular portion of one of muscle-cells of same separated and highly mag- 

 nified, showing its internal loculated structure and central nucleus. 



* These two figures should have formed part of Plate XXYII., with the others (figs. 20-24) illustrative of 

 the anatomy of Draeitn:ulus med'inends. 



