450 



REPORT OF STATE GEOLOGIST. 



present time. The Marsupial type of mammal is the most primitive 

 and the opossum as a race has existed for epochs, while one after 

 another of the more specialized groups of mammals have become 

 decadent or entirely disappeared. 



Even now, when he has come into contact with civilized man, 

 the opossum is holding his own very well. In some parts of Indi- 

 ana the species is not so numerous as it once was, but it is still very 

 generally distributed and even lives in the outskirts of towns and 

 cities. 



Its den may be in a deserted woodchuck hole, a hollow log or 

 tree, a natural cavern, a sewer or any other conceivable place that 

 will afford shelter. There, in a rude nest of dried grass, the young 

 are born. The usual number of a litter is from six to ten, but it is 

 said that as many as sixteen are sometimes produced. There are 

 two or three litters in a season. 



The young are less than an inch long when born and are blind 

 and naked with imperfectly developed limbs and organs. The 

 mother at once thrusts them into the pouch on her abdomen. They 

 secure hold of the teats and the lips grow about them, so that the 

 young cannot be removed without tearing the mouth. At this 

 stage they are entirely helpless and do not even suckle, the milk 

 being forced into their mouths by the contraction of special muscles 

 about the mammary glands of the mother. They remain in the pouch 

 for some weeks and attain a length of four or five inches before 

 they leave it. For some time longer they remain with the mother 

 and a second litter may be born and placed in the pouch while the 

 first is still running about her back and clinging to her tail. 



Most people know something about the peculiar manner in which 

 the young opossums are nurtured, but there are many fables and 

 wrong ideas on the subject. A few years ago the author saw a 

 letter written to the Smithsonian Institution by a Virginia gentle- 

 man who claimed to have been a student of natural history for 

 forty years. He asserted that our ideas of the breeding habits of 

 these animals are all wrong and that 'Hhe young grow out from the 

 abdomen of the mother like cherries on a stem." The writer also 

 has a letter before him from one of the pioneers of this State, assert- 

 ing that gestation takes plac^e in the pouch of the mother and that 

 there is some direct connection between this pouch and the internal 

 reproductive orgnnw. It is needless to say that both ideas are pre- 

 })osterous. Tlie enrly singes of the rej)r'oducti ve |)r()cess differ in no 

 essential wny Froiii those of domestic cnttle, r;il)l)its or other iruim- 

 mals. 



