CHROMOSOMES OF HIPPONOE AND MOIKA. I x ; 



plate- which -howed thirtv-ei^lu without any doubt. Tlmv of 

 them an- -hown in Fi.u-. 22. 2 ;, and 24. I al-o counted thirty- 

 seven in two very clear daughter plates of the same cell. 1 1 made 

 .: tew rount- \\here thirtx i\ -eemed to be tlu- number Inn in 

 tin - I was not -i in- that I had counted correctly. Other 



< ount- were made lull they \\ere equally valuele--. Tin- Toxop- 

 ncns!i's inait-ri.il \\a- too limited to permit definite conelu-ion- 

 as to i In art n. il nil nil M -r-. I am t m\ inred that morr than thirty- 

 -i\ < lironio-onie- occur in some eggs An .irtii.il determination 

 i- dilhi ult luit not impo ible. .\\t-ra-e- in a ra-r of thi> Mrt 



\\ hatr\ i r i In- morphological rrl.nion- of the In >ok to the otlu-r 

 mi-mlii-r- o| the roin|.Ie\. thrir nui-ideralioii lead- u- toa rero^ni- 

 tioii o| |ni iMe e\i-teiire of further aiKunalou^ iniidition- in thi>l 

 Bpecil All unequal pair- o| heterOchrOmOSOmeS Or unpaired 



heterochromosomes ol pi- ]'-i rvation find a |>lare in the 



M-rie- po-tulati-d |p\ MtAi-n-. ' I I. \\hirli. liei;inninu \\ith ( 'nlfx 

 and Theo :':::. v. : ichromosome occurs, includes all 



>t iln \aiiou- mn-i|iial pair- and end- \\itli form- ("iitainin^ an 

 odd ! unpaind rliroiiio-onie. \\ r ma\ imagine all of the mein- 

 bers in thi- series di ii\rd !r"in f'-rm- analo-.iu> to Culcx \>\ ihe 



dual dim in in ion and Imal elimination ol one chromosome Iri-m 

 |i.iir. A iimini; thai the hook in ////'/""""' i- 'he 

 nic.|-|)hoi : r.il ei|iii\.ilent "t the odd ehi'omo-ome or the l.u. 

 meml>ri Ol i inn ;n.tl |>air il follou- that thi- element eannol 1 >e 



"iinletl lor in thi- manner. < >n I In- roinrar\ WC mu-i conceive 



I the i haii^e iri-m the < heterochromosome i\pe io ihe 



7/;/'/" 1 ""' 'M"' '" ha\e COme about l.y all ilirrea-e ill the -i/e 

 of one member of a -omatir jiair. It i- i|iiite a- reasonable l> 

 -up|>o-e that the e\olutionary processes \\iihin the nurleii- in- 

 \ol\e an increase in the amount of rim-matin a- it i- to a nine 

 that the\ are a. v unpanied b\ it- elimination. In -up|)ort o| 

 thi- \ie\\ \\e have the (art that the hook i- the lar^e-t element 



in the ////V'"""' complex. 



i: \Yil-.-n. in .li ' XII.. T.U. X\"!.. 



.l.iu.clH' -h"\vini4 .57 >. '"' "'" -"I"'-- ' '" 



i-\|il.iii.iti.-n "I th'- liu'.ir -ii.it tin- nuinl.i-: i-int'-i- 



.-11111; in ihi-i ouuii'i-tion. In carln-i p.ip.-i- li>- rai-.- 1 iln- qu t" \\ln-tlH-r 



tin- niunt.iT \\.i 



