366 



ORNITHORHYNCHUS. 



stances which first attract attention in these singular 

 objects are the total absence of hair, the soft and 

 flexible condition of the mandibles, and the shortness 

 of these parts in proportion to their breadth, as com- 

 pared with the adult. The tongue, which in the 

 adult is lodged far back in the mouth, advances in 

 the young animal close to the end of the lower man- 

 dible, and its breadth is only one line less in an 

 individual four inches in length than it is in fully 

 grown animals ; a disproportionate development, 

 which is plainly indicative of the importance of the 

 organ to the young ornithorhynchus, both in receiving 

 and swallowing its food. On the middle line of the 

 upper mandible, and a little anterior to the nostrils, 

 there is a minute fleshy eminence lodged in a slight 

 depression. In the smaller specimen this is sur- 

 rounded by a discontinuous margin of the epidermis, 

 with which substance, therefore, and, probably, from 

 its having been shed of a thickened and horny con- 

 sistency, the caruncle has been covered. It is a 

 structure of which the upper mandible of the adult 

 presents no trace, and Mr. Owen regards it as ana- 

 logous to the foetal peculiarity of the horny knob on 

 the upper mandible of the bird. He does not, how- 

 ever, conceive that this remarkable example of the 

 affinity of the ornithorhynchus to the feathered class is 

 necessarily indicative of its having been applied, 

 under the same circumstances, to overcome a resist- 

 ance of precisely the same character as that for which 

 it is designed in the young bird, since all the known 

 history of the ovum ornithorhynchus points strongly 

 to its ovoviviparous development. The structure of 

 the eyes is indicated by the convergence of a few 

 wrinkles to one point ; but the integument is con- 

 tinuous, and completely surrounds the eyeball. In 

 the absence of vision in the young animal, strong 

 evidence is afforded of its being confined to the nest, 

 there to receive its nourishment from its dam ; and 

 this deduction is corroborated by the cartilaginous 

 condition of the bones of the extremities, and by the 

 general form of the body : the head and tail are 

 closely approximated on the ventral aspect, requiring 

 strength to pull the body into a straight line ; and 

 the relative quantity of integument on the back and 

 belly shows that the position necessary for progressive 

 motion is natural at this stage of growth. Mr. Owen 

 describes other external appearances of the young 

 ornithorhynchus, and then enters at considerable length, 

 into its anatomy. The stomach is nearly as large in 

 an individual four inches in length as in the adult 

 animal. In this specimen it was found filled with 

 coagulated milk, and no trace was visible, on the most 

 careful examination, of worm or bread, on which, up 

 to the time of his discovery of the mammary secretion, 

 lieutenant the honourable Lauderdale Maule had 

 believed that this individual had been sustained. A 

 portion of this coagulated substance was diluted with 

 water, and examined under a high magnifying power 

 in comparison with a portion of cow's milk coagu- 

 lated by spirit, and similarly diluted. The ultimate 

 globules of the ornithorhynchus's milk were most dis- 

 tinctly perceptible, detaching themselves from the 

 small coherent masses to form new groups : the cor- 

 responding globules of the cow's milk were of larger 

 size. Minute transparent globules of oil were inter- 

 mixed with the milk globules of the ornithorhynchus. A 

 drop of water being added to a little mucus, it in- 

 stantly became opaque, and its minutest divisions 

 under the microscope, were into transparent angular 



lakes, entirely different from the regularly formed 

 granules of the milk of the ornithorhynchus." 



There are many highly interesting points in these 

 remarks of Mr. Owen, which would bear, and indeed 

 which require, more making out, and less disposition 

 o be fettered by the insinuating doctrine of affinities, 

 .hat appears even in his account. The hardened 

 inob on the upper mandible, for instance, cannot be 

 regarded as having the slightest resemblance to the 

 enlargement in the tip of a young bird's bill, and that 

 for this obvious reason ; the appendages to the jaws 

 of the young ornithorhynchus, are not mandibles, but 

 really lips adapted for sucking, and the tongue is a 

 sucking tongue. The knob upon the upper lip is 

 clearly intended for assisting the young one in ob- 

 taining milk from the mammary apparatus, which, 

 from the large size of the stomach, it evidently does 

 in very considerable quantity. This agrees with the 

 very partial development of the young as at first seen, 

 and the maturity at which they arrive before leaving 

 the mother, and also the comparatively rapid rate at 

 which this development takes place. In many of the 

 regular mammalia, and even in the human subject, 

 the inside of the upper lip is provided with a knob 

 much firmer than the rest of its substance ; and there 

 seems little doubt that this knob operates in some 

 way in pressing the mammary apparatus. There is 

 no regularly formed teat upon that apparatus in the 

 female ornithorhynchus , and thus there is little doubt 

 that the knob upon the upper lip assists in pressing 

 the mammary glands so as to obtain the requisite 

 supply. 



The quotations and remarks which have been 

 made, embody the greater part of the knowledge 

 which we at present possess respecting the phy- 

 siology of this very singular animal, and, taking the 

 general scope of them, they completely refute the 

 notion of its being oviparous, and render that of 

 its being ovoviviparous exceedingly doubtful ; but 

 till the facts between what has been last observed of 

 the internal germ, and what first of the produced 

 young, have been ascertained so as to complete the 

 series, some doubt must remain ; and doubt of such a 

 nature, as not to be removed without the greatest 

 difficulty. The chief difficulty appears to consist in 

 this, that the female, at the time of parturition, never 

 makes her appearance ; and the nest is so concealed 

 in its entrance, that it is scarcely possible to detect 

 her there, except by one of those accidents which 

 can be but rarely looked for in those wild and unfre- 

 quented parts of a savage country which the animal 

 inhabits. All the authorities agree, that the burrows 

 of these animals are formed in secret, and the en- 

 trances of them are carefully concealed. The water 

 line is the elevation at which the burrows of aquatic 

 mammalia generally open ; but these have two open- 

 ings, one below the surface of the water, and the other 

 at a considerable elevation above it, but always so 

 hidden among the herbage, that it is impossible to 

 know where to look for them. They are dug to a 

 great length, sometimes as much as fifty feet, and 

 seldom less than thirty. They are winding in their 

 direction, and incline upwards ; but the animal never 

 throws up any heaps on the surface, or leaves any 

 excavated earth at the entrance. It is probable, there- 

 fore, that it bores into the earth by the forw;ard 

 pressure of its body, as the mole sometimes does, and 

 does not remove any of the earth with its claws. The 

 fore paws, which are the effective digging instru- 



