14 8(S.S.4SO) 



THE MONONCHS 



the males never have been seen. At a time previous to the development 

 of the vulva the gonads of the female produce minute spermatozoa, which 

 are sent forward and stored in a special portion of the uterus next the 

 proximal end of the ovary. In the only species so far carefully examined 

 in this regard these minute spermatozoa are known to be functional, at 

 least to the extent that they enter the ova, which then proceed to form 

 polar bodies and begin to segment. However, these particular investiga- 

 tions, made by the author and further recorded in figure 2, have been 

 confined to the single species M. longicaudatus. Possibly the phenomena 

 are different in other species. 



Male Sexual Organs 



Spicula. The tail end of the male is invariably like that of the female 

 in general form and size, except that it is more strongly arcuate; it 

 differs however, in some instances, probably in all, in the possession of 



comparatively well-developed papil- 



FIG. 15. Tail end of . 



M, obtusus after Biitschii. IK. and particularly and universally 



The spicula in this spe- 



cies are exceptionally long in the existence of a ventral row of 



and slender. The male o ^_ ... 



papilla (ppi.) and supple- 8 to 20 more or less equidistant sup- 



mentary organs are very . ..... 



well shown. The spicula plementary organs immediately in 



pr0tudabndare front of the anus. The two well- 



gude 



bysiend e racces 



S*.eft 1 e." iiE developed arcuate spicula are 



of 



equal size, and are always accompa- 

 nied by two distinct though small accessory pieces, a 

 right and a left. Only exceptionally are the spicula 

 long and slender; usually they are somewhat uniformly 

 arcuate, and appear to be subacute and of somewhat 

 uniform width throughout, at least when viewed in 

 profile, and about one and one-half times as long as the 

 anal body diameter. Usually each is strengthened by a 

 median longitudinal refractive piece. They are never 

 prominently cephalated. The accessory pieces are lo- 

 cated some little distance inside the anus, alongside the 

 spicula, which they may appear to cross when viewed 

 in profile. These accessory pieces are usually a little 

 narrower than the spicula, and 2 to 4 times as long as 

 wide. Distally they usually end in two subacute points, 

 often so arranged as to form a small U-shaped figure. When at rest the 

 accessory pieces usually appear as if at about right angles to the axis of 

 the body. They are not cephalated. 



Supplementary Organs. Sperm. The supplementary organs vary in 

 number up to twenty. The hindmost is located immediately in front of 

 the anus, and may be a little farther removed from its nearest neighbor 



