JUNE 19, 1932 



COBB: METOXCHOLAIMUS PRISTIURUS 



449 



Fig. 4 Tail 

 end of M. pris- 

 tiurus, Male X 



wnstrx 



off from the ejaculatory duct by 

 a distinct constriction, 56, is one- 

 fourth; and the testes average 

 one-fourth to one-half; as wide 

 as the body. There is a con- 

 striction midway in the vas defer- 

 ens, 37. The blind end of the 

 anterior testis, 70, directed for- 

 ward, is about two neck lengths 

 behind the cardia, while the blind 

 end of the posterior testis, 76, di- 

 rected backward, is about five 

 tail-lengths in front of the anus. 



Beginning between the renette 

 cell and the cardia (at 23) there 

 is a long, straight, tapering ac- 

 cessory gland, 51, emptying back- 

 ward into the beginning of the 

 vas deferens, i.e., at the point 

 where the two testes join it, 33. . ^. 



This gland, accessory to the 22 fn '' 44TCt 

 gonads, is, no doubt, a re- 

 duced homologue of the demanian system of the female. A possible func- 

 tion is the production of cement (aseptic?) used in copulation. 



The primary spennatocytes, 69, near the blind end of the testes are about 

 forty microns in diameter. About twenty of them would be required to 

 span the corresponding body diameter. Full grown spennatocytes, 4, 36, 

 occur farther along the testes in rouleaux, and are two-fifths as wide as 

 the body of the nema and one-third as long as wide. Nearly simultaneous 

 synapses and reduction divisions of a full grown sperm are often in progress in 

 one or the other testis, 2, 3, and the members of the resulting quartet, 2, of 

 smaller cells, that is the resulting spermatids, are somewhat equidiametral 

 and are about one-fifth as wide as the body. 



.COP MM 



X1000 



Fig. 5 Cross sections of Metoncholaimus pristiurus through the regions of the 

 moniliform glands of the female and the spicula of the male respectively. 



