152 



The Journal of Heredity 



and the act of self -amputation takes 

 place later. 



It follows from these facts that the 

 above-mentioned openings of the fe- 

 male tail end of Ag. dccaudata and 

 perhaps of other female Mermithids 

 can not be regarded as rudimentary 

 anal openings, but must be sex open- 

 ings, as all tissues which are homo- 

 logous with the posterior intestine, the 

 rectum, and the anus of the majority 

 of adult nematodes are dropped l)y the 

 Agamermis larva when the act of self- 

 amputation takes place. 



Furthermore the relative frequency 

 of these openings, and the fact that 

 such female tail ends form a graded 

 series linking the normal female and 

 the normal male tail end, speaks against 

 the conception that they are anal open- 

 ings. If we take this grade of trans- 

 formation out of the series, the other 

 members of it could not be understood 

 or placed, whereas by regarding it as a 

 reduced male sex opening, it completes 

 a natural structural series that can be 

 understood without difficulty. Hag- 

 meier too regards these openings as 

 rudimentary male sex openings and 

 not as vestiges of an anal opening. 



Figure 6 is a sketch of two female 

 tail ends, one of which has not only 

 the male sexual opening, but also a 

 number of male papillae. The other 

 represents a further step to more pro- 

 nounced intersexuality. There is a 

 rudimentary male sex opening, and 

 also two very small spicula and traces 

 of two male papillae. 



Much more pronounced is the inter- 

 sexuality of the female of which the 

 tail end is pictured in Figure 7. 

 The first gives a lateral, the sec- 

 ond a ventro-medial view. A distinct 

 sex opening is present as well as spic- 

 ula, which are asymmetric ; the spicu- 

 lum of the left side consists of two 

 separated pieces. Some tissue belong- 

 ing probably to the sheaths of the 

 spicula is also developed. Numerous 

 bursal muscles and male i)ai)illae are 

 also present, the latter not fully grown. 



The tail end of an intersexual fe- 

 male sketched in Figure 8 is of par- 



WELL-DEVELOPED SPICULA 



Figure 7. Two views of a female with 

 well developed spicula {sp), bursal muscles 

 {bur muse) and papillae ( $ ppL). It must 

 be borne in mind that all the individuals 

 shown in these illustrations have in addition 

 to the male organs a complete and function- 

 al set of female organs. Left, lateral view; 

 right, medio-dorsal view ; sp s, spiculum 

 sheath. 



ticular interest, having four pieces of 

 spicula ; morever, they are asyminetric 

 left to right ; those at the left have the 

 general form of spicula, the one being- 

 smaller than the other. At the right, 

 there is, besides a somewhat normal- 

 shaped but small spiculum, a globular 

 body. Tissue has developed around 

 the spicula. also a sex opening can be 

 observed as well as some few bursal 

 muscles. IMale papillae of more rudi- 

 mentary character are also present. 



Three more advanced cases of in- 

 tersexuality were mentioned and de- 

 scribed by Meissner in Ag. albicans. I 

 myself have not yet seen such high 

 grade intersexes. In these three si>eci- 

 mens of Meissner even the size seems 

 to have been involved in the transmu- 

 tation toward the male. He states that 

 all three of these females were dwarfs, 

 compared with normal females, and 

 had only the length of males. It ac- 

 cords with this that the other male 

 characters also were more developed 

 than in the specimens above described. 

 Meissner says that the tail ends of his 

 females were completely masculine, 

 with two normally formed spicula of 



