7JO 



MAMMALIA. 



may exist in other parts of the Ornithorynchus, it is most import- 

 ant to the question of its generation to bear in mind that it mani- 

 fests no resemblance to the Bird in the disposition of its pubic 

 bones. 



From the above considerations it is therefore probable. that the 

 young Ornithorynchi are produced alive ; yet still the reader will 

 perceive by the closeness of the reasoning brought to bear upon 

 the subject, how nearly the oviparous and mammiferous modes of 

 generation are approximated by the interposition of these con- 

 necting forms of Vertebrata. 



(835.) But if from these arguments, derived from the anato- 

 mical construction of the female parts, it is allowable to conjecture 

 that the Ornithorynchus is ovo-viviparous, using that term in a 

 strictly philosophical sense, the difficulties of the case are by no 

 means removed ; and granting that the contents of the ovum are 

 barely sufficient to nourish the embryo during the very earliest 

 stages of its developement, we have yet to learn how the fetus is 

 matured after the exhaustion of this supply. There is no reason 

 whatever to suppose that a placenta exists at any period of uterine 

 gestation ; neither is there a marsupial pouch in which the pre- 

 maturely born young can be carried about and supplied with milk ; 

 so that whether the young Monotreme be developed in the uterus, 

 or out of the uterus, we are equally at a loss to understand how its 

 nutrition is provided for. 



In this state of uncertainty, the 

 anatomy of the young Ornithorynchus, 

 examined at as early a period as pos- 

 sible, becomes a subject of extreme 

 interest ; and fortunately Professor 

 Owen has been enabled to add obser- 

 vations upon this subject to his other 

 valuable researches relative to the 

 generation of these creatures.* The 

 annexed figure (Jig- 328) is a por- 

 trait of one of the specimens dissected, 

 and from every appearance it could 

 not have been more than a few days 

 old, that is, supposing it to have been 

 born at an advanced period of its de- 

 velopement. It was as yet blind, and the situation of the eyes was 



* Owen, on the Young of the Ornithorynchus paradoxus. Trans. Zool. Society, vol. i. 



Fig. 328. 



