Table 4. — Numbers of male raccoons observed with broad, thin, or closed epiphyses at various months of age; 45 intact and 7 cas- 
trated individuals were examined one or more times each. Ages were estimated for all but 7 individuals, whose ages were known. Num- 
bers designating castrated animals are in parentheses. 
Epiphyseal Condition * 
Epiphyseal Condition * 
Months Months 
of Age Broad Thin Closed of Age Broad Thin Closed 
6 aS a 1 SEF nee cy ck Ee I eR (1) 7 4 
eRe 4(1) Gio setters, aict staces. ahscao, aia 1 1 
a 5a eee 3(1) 1S eee hiracai aeiect Say eee or eae 4f 2 
ys ah So See 47(1) ZO irs tate hs Moknd Seley. Gar (1) 2 
Se pee hice cress 5 Pelirabtche oitw aati eshaeniatia hs 1 1 
oo Se AES Se 5(1) DDN is sie halves seatsoecn chin thee, as aya 
MUM ieicio esa reas 3 t(2) Ro i cael ert Neh AONE ied or TS (1) 
oa agit DARE ie sterae nr omit ome Hie ae 1 
2p oe 1 Dias teks ae awe ee Meh e 
62 oa ao 4 4 Gipsy Hn, dul sheen) weit 
14 sod tls BN ee ee %) a 1 Dilines  ponthe noise oa plnu poain ra ckee> 1 
OA: 63 e ee 2 1 20 Sra mvc tac are ie seys te soe eas 
|. on 0 AS Sh See Eee Eee 1 AO Srareh i ere tecta sexta si kt ore ae 1 
*In an animal whose epiphyses were photographed more than once, only the maximum age at which broad epiphyses were seen, only the minimum 
and maximum ages at which thin epiphyses were evident, and only the minimum age at which epiphyseal closure was detected are included in this table. 
+ One animal reared as a pet is included in this number. 
i Table 5. — Numbers of female raccoons observed with broad, thin, or closed epiphyses at various months of age; 52 intact and 7 cas- 
_ trated individuals were examined one or more times each. Ages were estimated for all but 2 individuals, whose ages were known. Num- 
bers designating castrated animals are in parentheses. 
Epiphyseal Condition * 
Broad Thin Closed 
Months 
of Age 
ay 
~ 
i) 
FPeENUKWNERODMWHEE 
eS 
= 
Epiphyseal Condition * 
Months 
of Age Broad Thin Closed 
eS aA eer re Monts 1 3 
US ieerdeto selena atresia Be 1 
IIS) Sa rOree ica retract ooh ncn cree 7 1 
7) tes Secrerie Orr evar Pere Orrea 2(3) 
Dian Sie Ae aheyetchereracs sc ushavahesoertet (1) 1 
DO AEN oi dies Neheln) Cha ORO 
CONAN HNC cite CLOT RR NER acto 3(1) 1 
DAEs fe vate cst sth a aete ec edecec ere one (1) 
Dorey oS ay eF) eas ease OU eet be 
7A ary Ae Sica See en ate 1 1(1) 
7A hestle, ATER ARE eR EOS C 
DOP T ete yaiPases pay seer 1 
DO ees tay eres atshs pane ote sce Leaver 1 1 
DU ear eats sets ls. wrsley ant eaten 1(1) 
SI Fe vate) chap iia a) Mra peia co Santee 1t 
*In an animal whose epiphyses were photographed more than once, only the maximum age at which broad epiphyses were seen, only the minimum 
and maximum ages at which thin epiphyses were evident, and only the minimum age at which epiphyseal closure was detected are included in this table. 
+ The ulnae in this animal had closed. 
X-ray photographs and/or direct examinations of 
radii, ulnae, and some humeri in 52 intact female 
raccoons, some wild and some captive, revealed that: 
(1) a broad plate of epiphyseal cartilage was present 
between the diaphysis and the epiphysis of each radius 
and ulna in 45 females ranging from 2 to 17 months of 
age, 44 being 15 months of age or less, and 1 being 17 
months old, table 5; (2) thin epiphyses were present in 
23 females ranging from 14 to 31 months of age, some 
of these animals retaining them for periods varying 
from 4 to 11 months, and 9 females in this group had 
thin epiphyses after 19 months of age, but none had thin 
epiphyses at 13 months of age; (3) the ulnae were 
closed and the radii thin in 1 captive, nulliparous fe- 
male approximately 31 months of age; and (4) epi- 
physeal closure occurred in 6 females after they reached 
the age of 18 months but before they reached 31 months 
of age. These data from females show an extensive 
variation in epiphyseal development as related to age, 
but the age range within which epiphyses closed in 
captive females did not differ from that in wild females 
in the small number of raccoons available for examina- 
tion. In two parous, captive females of unknown ages, 
the epiphyses closed when one was at least 39 months 
of age and the other at least 42 months of age, but 
these animals are not shown in table 5 because only 
animals of known ages were listed there. 
During the hunting and trapping season in Illinois, 
epiphyseal plates of the radii and ulnae furnish an ade- 
quate means of separating females into adult and 
juvenile age classes. Most females found with broad 
epiphyses at this season were juveniles (4-10 months). 
9 
