Title: Bulletin Identifier: bulletin3119731977illi Year: 1918 (1910s) Authors: Illinois. Natural History Survey Division Subjects: Natural history; Natural history Publisher: Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division Contributing Library: University of Illinois Urbana-Champaign Digitizing Sponsor: University of Illinois Urbana-Champaign

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Text Appearing Before Image: 66 Illinois Natural History Survey Bulletin Vol. 31, Art. 2 Ampulla Prostot

Text Appearing After Image: Vas Deferens -Schematic drawing (side view) of the reproductive system (X 0.85) of an adult molel Fig. 12.. raccoon. unite inside the prostate to form a com- mon duct. The many compartments of the prostate gland open into this duct system. The OS penis or os baculum (bone of the penis) is well developed in the rac- coon. Its stage of development has been used to separate males into two age groups (Sanderson 1950: 395-396; 1961a: 11-14). The os baculum was once used by tailors as a ripping tool for taking out basting threads (Jaeger 1947: 297). We found several raccoon bacula that had been broken and then healed. Sand- erson (1950: Plate 11) showed a photo- graph of some of these bones. Our data from wild males shed some light on pos- sible causes for these broken bones. Dur- ing four hunting and trapping seasons in Illinois (1957-1958 through 1960- 1961), 7,233 bacula from juvenile rac- coons were examined. Forty-three (0.6 percent) of these had been broken but were healed or healing, and 238 (3.3 per- cent) were freshly broken. At the same time, 4,152 bacula from adults were ex- amined. Eighty-six (2.1 percent) of these had been broken but were healed, whereas 41 (1.0 percent) were freshly broken. These data indicate that most of the breaks in the os baculum of the raccoon occur in juveniles. The bacula of juven- iles are much softer and more easily broken than are those of adults. Hunters often shake a raccoon out of a tree and let their dogs fight it. Fighting with" dogs could account for the freshly broken bones found in both adults and juveniles, and the more durable bones of adults would explain the smaller percentage of freshly broken bacula found in older raccoons. Females The raccoon uterus (Fig. 13) is some- what intermediate between the bicornuate uterus found in the pig and insectivores, and the bipartite uterus found in the cat and dog. There is a single cervix and the horns are distinct, but after the horns join externally to form the single, small uterine body, the uterine lumina remain separate — even though this separation is not apparent from the outside — to a point near the cervix. Llewellyn & Enders (19546: 439) re- moved one ovary, ovarian capsule, ovi- duct, and proximal end of the uterine horn in each of two raccoons. After closing the cut ends of the uteri with sutures, they released the females. When retrapped the next year, each female was carrying three embryos, two each in the normal horns and one each in the ovar- iectomized horns. Thus, even though the internal separation of the uterus ex- tends nearly to the cervix, ova can pass from one uterine horn to the other. In our study some indirect evidence of transuterine migration of ova was noted. In a few cases more embryos were found

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