ARE PARTICULAR CHROMOSOMES SEX DETERMINANT 9 



capable- of reproduction and conjugation alone. Thi- hold- true 

 in tlu- Metaxoa, both for tin- i^erm cells and for the per-on-. and 

 tin- male is rhara< teri/ed by hi- power to conjugate or fertili/e, 

 tin- female \>y her power to reproduce. A micro^aniete in the 

 I'p.io/o.i. or a -permato/onn or male per-on in the Meta/oa. i- 

 an indi\ idual that ha- lo-t the power of reproduction in becoming 

 -pe< i,ili/ed for tli !" conjugation. Sexuality i- then the state 



of occurrence of di--imilar conjugating individual-, and the 

 -ential point in thi- di imilarit y i- that only one kind of the-e 

 indi\ idual- ha- the power to reproduce. Thi- -imple interpreta- 

 tion w.i- entiri-ly overlooked b\ ' and Thom-on in their 

 theor\ of 'The b.\olution 3ex.' ". 



The germ cells are then not w it lion t & Morgan would ha\e 

 us believe, but have an actual ^x utility with re-pec t to each other, 



an o\ um bein- lemale and a -permalo/, >n male; a- well a- a 



\nality with j 1 to the kind of individual they 



may engender. \\ f are here ( <ni< . -i m d with the i|iie-tion of the 



determination b\ particular i lironm-oine- of |>i-o-pecti\i- sexu- 

 ality . 



I urther, a hermaphiodite i- bi-e\ual. and ii therefore 



pecti\el\ bi-e\nal. engendering both kind- i-t gametes. Thi- 

 iiulicate- that an egg nia\ i on lain potentialK the chara< t< rs of 

 both g< .r better -taled, that both >lat< max ari-e 



I'l'-m the -anie egg. Thi- ma\ abo be true for -pecie- thai are 

 no] hei-maphiodile, for a female indi\ idual fre(|Ueinl\ sho\\ - 

 Certain male charai teri-tic-, and a ma! dn female <|ualili -, 



even it in a more <,r less latent condition. The-e londition- 

 indieale that ai not (ontain pro-| ie. i i\ ely one -e\ual 



-tale to the e\i lu-ioll of the other, but father that malcnc-- and 

 femalene-- are closelj iateil phenomena that may inter- 



change within the same individual; a po--ibility -u^>;e-t-d by 

 M 'i -an 'I'n 



Bearing th< se idea- of the \ a hie of sex in mind, the following 

 main objection- max be made to the h\pothe-i- that particular 

 allo-ome- act ' minani- : 



I. While the phenomena appear to admit ot a -impK 1 explana- 

 tion in cases w hen- there are only a pair ot idiochromosomes, or a 

 .-in-le moiio-ome, iii the spermatogenesis, ohcn the condition- 



