28 



ART. ê. — EKITAEO NOMURA: 



The wall of the duct consists of two layers, as in the case 

 of the funnel. The ciliated cells of the inner layer are thin 

 (2-3 [j) and nearly semicircular in shape, so that two or three 

 cells are sufficient to form the whole circumference of the canal. 

 The plasmic strands are stouter than those of the funnel. The 

 nuclei are exceedingly elongated, measuring 9-10,« by 1.5-2.0 /*, 

 and lie in the middle of the cells, with their long axes perpen- 

 dicular to that of the tube. The outer connective tissue layer is 

 very thin. 



sspth 



— sept 



t ospth sb fun ov 



Fig. 20. 



L. gotoi. Schematised longitudinal section through the left ventral setal line of segments 

 X-Xn, showing the mutual relations of the genital organs. Prostate gland omitted. The 

 posterior end of the contorted spermatheca is situated directly in front of the sperm-duct 

 funnel, sspth — saccular portion of spermatheca, dspth — duct-portion of spermatheca, ospth — 

 spermathecal pore, sept — septum, t — testis, ov— ovary, sb — seta-bundle, fun— sperm-duct fun- 

 nel, vd — vas deferens, at — atrium, opr— opening of prostate gland into atrium, dat — atrial 

 duct-portion, p — penis, chs— chitinous penis sheath, os — male pore, od — oviduct, dv — dorsal 

 blood vessel, per — peritoneum, lm — longitudinal muscle, cm — circular muscle, hyp — hypoder- 

 mis, cut — cuticle. 



c. Atrium. This is a spindle shaped organ which receives 

 the vas deferens a,t one end and leads to its own duct portion 

 at the other. The widest part of the organ lies at its middle 

 and is more than three times the diameter of the vas deferens. 

 It is also circular in cross -section. 



The wall of the atrium consists of three layers. The outer 

 layer is the continuation of the connective tissue of the vas 

 deferens, and is followed throughout the organ by a compact muscle 

 layer which appears to be circular but may possibly be spiral. 



