PT a og 
IN THE GONAD OF MALE 
ee eae 
LOGOUS CHROMOSOM 
ACRIDID 
The point at which the non-disjunction occurs is indicated thus: = 
Complexes in which an accessory is present are denoted by (x) 
Genealogies of complexes are indicated by broken lines 
= eS Sa Re 
qotes From Nlormal| Gametes. _|Non-disjunction_ Of A Euchromgsome Pair nites 
Fyod Ne aberrant ratever | 3) dyadsx)_— | -23 dyads(d— —|- - 19 dyads (xy - - | - 29 dyads - - | - 32 dyads) -- | — 23 dyads —-.-} --stetras + dead) _ riya ayaa 
wma) covrt_Unroghevt 
N-DISJUNCTION OF A PAIR OF ENTIRE HOM 
rat a 
No Z, One atypical second . : tnopaer 
un dyed 5) oe Spertetacid iy 139 dyadsq _| 23 dyads@)_. _|_ _ 39 dyadsqu___|_ _ 33 dyads _ | _ 33 dyadsiev- | a9 dyadsqey_ |i tetas ¢ dyad yy 19 
ea syed epee : : 3 
seer 29 dyads | 73 dyadsiy | _ £3 dyadstyy_ _| 23 dyads = 33 dyadsiy — | 93 dyads 
SEE, 
spermatids. 
China 
easy | 33 dyads. | os dyad | _ as dyes _ _ |) _ 3 dyads) _ _ & menahi(y| — — —iitstradseadyeee| 
* 
=a dyed | art 
ing, fem . 
‘normal complexes, Wnermate; 23 dyads | tetrad» dyed] — — ‘ 
sc oe Bier i om able, hence gw te many «ifs lacking in abe fill . 
re r one 23 dyads —| 23 dyadee) | _ 29 dyadsay _ _ | _ 23 dyads cr) _ __ |) menaisyenttion es eM — —M tetrads +3 dyads SRnee q 
"opt males 23 dyads _| — — 2s olyadsign _ | _ _etetreds + 1 lved ow. -| 3 
J— — — Wer-casbig, Nente ane falizie of thm. dala 
a a 
0 dyads rt 
“peepiaircs rs ner dyads | 23 dyadstl | — 23 dyads c+) 
eno bat: ie graee ee tet ; De i eee 
Fics dyads (Ne: t fieiet aE Tha. deGvitive gan wisinge 
gaits oe dye styyaal, ana om 33, dyads ia} | 22 dyade(e) __srordarmtmr is rads | — 24 dyedsigh - | — 
= Comal: ieapas im Nos 4, Saga 6 
frormals; 23 dyads te 
eae-Aait the folliclas pithe dfiifive genad Miuing—— | 
(No. Defi a bie, hen 
= — 
iainanesarmat” | 35 dyads | Maseaghimmonh — seeped — 
aia 
Veesittene eetcee faiicle, br waaay). [293 dyadsqo — = 
Tl. Zygotes From A Normal By An Atypical Gamete. Non-disjunction Of ernumerary Fair Of Chromati 
faith  dyadt |Nod- No aberrant mitsses. by free segrega 
[foe 19 dhadig| Covet consistent threvghout, 29 dyadsuy |_ .24dyadew_ | __24 dyads w) _ _ | _ 24 dyads — _|_ 34 dyadsw_ _ | _ 34 dyadsts) — — 1 _i/tetrads +2 dyads(ai _JJof te arc 
jes in 4,5,6 and [7 > 
er 
and 5 
lacitm oo dyads 
bach 0 
re vdpds |No./0, One exceptional 
ond eparmater 
ten 9 Seatac tec peel sper 
mann 
narsdiyeretion} — gr 
(3 dreds Uy remands — 
24 dyads) | __24 dyads | _ 34 dyadsixy__ | _ afdyadsixy_ _— | _ 24 dyads = L _ aa dyads | i fetrads + x dyads) __ 
(A with dyads jcomplena® fy dyads — 
fim dean as in No 
saya: 
ve Tae 
sith dada yg 11 ris auselicat eS 
itis dyed 
ihe uo dyads) 
ore dyads 
f a hts, Pe Siete PF Fe 24 dyads |. _24 dyads) | _ 24 dyads — — — 234 dpadsoy_ — | 
dyads-—[— — — 1 dyads 
5 men di: 
35 monaduiey| _ /2 tetrads + | dyad )_ cindy) 
1 tetrads + 1 dyadies_ 
24 dyads(ny _ 
Slain dyadic ort ot the gonad is 34, 
an No9:. 24 dyadsts|__ yrtetrads +z dyad@!| as ans _f a 
A 
£3 eda 
Bae epRAE (a5 me — — 25 dyads _ _| — 12 tetrads 1 dyed y_|_ 
f i. jn Node 
i} 
—74 dyadsix | 39 dyads) -_|_ 24 dyads) — — Din aintenction Us menain — —. 23 dyads — | _ 1) tetrad + 1 dyads 
vith n dyads aes 
Por adnan ere eed Sane et | 
or land deme of 38> The dipind| 
fain > duds Eelee far the rest of the | 
fran dating 
Poin Sits, 
las in No. -...24 dyads _ 24 dyads. dL _ i tetrads + 2 dyads | _ 
: | 
ith i ed FTAs ps mona —- 26 dyads) — —|— 
{e vy dyads) one sung & clblerd ecer otf 34 dyadsin| 24 dyadsco_| _ 24 dyads py — - ints meadi}_ 33 dyads 2 — -| akin Nos 12 ands 
Dibleid count for rest of im No9...34 dyads) 24 dyads ix) — + 
or Ibi 
lath ob dyAds loonad 24. Count consistent 
gas 1 dyedued Sor the etnicte 
of with) dyeds (NodS The count 13 ear 
; IPN Ga mena Ge 35 dyads — 4 
24 dyads(w)_|_ 24 dysdste)— hendaprtew eG Saisie 33 dyads) —— fas in 12,13 and | 
im Ned: 24 dyadewl_ _ 24 dyads eey_ _ |_ 
adyads— — 
fal the feuncles 
Te ae ellen ean eS A. tetrads +) dyad 
SF dyads [dipieid cont of 36 Br ayag inna is a ieite: Bees vanes Ke a +t dyadt— | — lig dyads — | — — - 19 dyads i, 
Di dytdsey kat 6 cont of 3a” 23 menadste__ a5 dyadsqy _ | _ 23 dyadsqy__| __23 dyadsg2 _ 1 a3 dyadsou _— _ Lyi tetrad + 1 dyad pa sae Wepre --- Se 
Be ayed Nolb. The dipleid cout ts 
V Fovlicle. 
Tio. 0 dysdipy couttant for the Feilicle. One~ — a — op dyads 
| 
otes From Two Atybical Gametes. Non-Hisjunetion Or A Super numerary Bir, 
TT Ne aberrant miter] 35 dyadipy.-|. 25 dydsu.|—35 dyadew —-1— 1 26 dyadiy. -|— -a5 dyads —— 1 —.16 dyads ix) — — | —ittetrads tidyadiy — 
—- ~~=/ dyads 
Soaeae doa)? 8" 
Fr censiatert Crrevghest 
Nol. One exceptional 
Faith 2 dyuh second spermatecyte 
Jute 0 dyads telophase OF Twe excel 
Spermatid comple 
ml] 55 yada | ps dyadew | _ aS dyads — —|_ — _25 dyads _|_ 25 dyads(y— — 4 — 25 dyads) _ _ 
0.19. One exceptional twa eat 
som on dyagy PESTmateente telepnate or * ; Yat es 
wit 1 dyads ltwe Oxceptimal Secon s tl ee . S " i 
$40 1 dlaimlspermatocste complexes aw dyadsty_ 4 35 dyadsia | _ as" dyadsty_ | _ _aSdlyadntel | 35 dyadswy_ _ | _ 25° dyads(x) ___ depearhaiidiat ade = = x7 dent yd cusses 
or four exceptional 
[spermatid Complexes 
can [Na 20. From fem © 
jatetrads + 1 dyadiv. 
nu totrads + & dyads, y 
many 
Gath 11 dyads as dyadsis)_ | _5 dyadsut | _ _g5 dyads) __ _|_ _ _a5 dyadsty) - 
- tate 0 dyaaio) 
_ pr tetrads + 5 dyads 
ejenyg tetrade + 1 otyad(n) — 
=i) tetrads + 2 dyads ~ 
=/A tetrads + 3 dyadsw— - 
1a tatrads +) dyadix)- - 
oxith v dyadt 
Poe y Radel = = tA dyads. 
~~ 26 dyadtwy - 
= = 35 dyads ei — 
ae dyadsih 1 25 dywdsy 1 25 dyadsixy — | ~ 25 dyactsy —_ 
ee dierTIONS & mena 
a5 im Weilt: 25 dyadats) 
—14 dyads) — | 
= 26 dyadsyj— — -|-} as in Nes, 26 and 21, 
— 3s dyads) = —|—, 
SP with a dyads 
@ with o dyads)! 
elophase (24 mor 
25 dyads | 25 dyadsiy_| — 35° dyadeqy — —.)) nen dighl 
a5 im Nal; 25 dyads fy} 
Path, 12 dyads jN0.23. The dipeid count Cepase; ees = 24 dyads) 
g with 19 dyads eee MS pene 48 dpalam,| — a5 dyeioyy =-)\ reo momamls = Cae dyadipa = 
dpa cone 
Eee S teortht or os as ines: 25 dyad — ag dyadsv 
give & ceont of 24 and 
fourth or less gire & 
No.24. The dipleid count c : 
Faiths dyads |e ee ie Fett bine — 2¢ dyads — —L _ 24 dyads. —|_ 24 dyads -— | - 24 dyadsq_ _ _ 4 _ iftetrads + 4 dyads ty 
$ with 7 dadity [aipierd count of 3, 2nd 25 dyads] by 
’ 0 
aes = 26 dyads (x) — | — 74 dyadsyy—-} —26 dyads - - | — 26 dyadsq - - - 
———S=— 
This chart illustrates what wide variations in the chromosome count within the testes may result from a single non-disjunction of a pair of homologous chromo- 
somes or chromatids. If more than one such aberrant mitosis occur the situation is much more complicated, but the effect on the chromosome count can be 
_as readily tabulated. The effect of the non-disjunction of homologous segments of chromosomes or chromatids can also be easily charted. 
It is assumed, for the sake of brevity, that a cell lacking a member of the normal complex is non-viable. 
Except where otherwise indicated, all counts are for metaphases. 
In the third type of zygote above, a pair of homologous supernumeraries may, of course, both be inherited from either gamete. 
