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I have already mentioned that this process does not occur in Teleosteans whose ovaries were studied by me. These were species of Teleosteans in which fertilisation is external. Lin. Marshall himself examined sections of the corpus luteum of Ornithorhynchus and saw much hypertrophied and apparently fully developed luteal cells, but no trace of any ingrowth from the wall of the follicle.
There is, too, the Tasmanian devil, a small but formidable animal, something like a badger, and the ornithorhynchus, or duck-billed platypus, which figures on some of the postage stamps. This want of energy is a fact, however it may be accounted for. Probably the emigration to Australia of some of the convict families, as above mentioned, has withdrawn some useful members of society.
Under these conditions it is obvious that diffusion of chemical substances from the young through the walls of the pouch would come to an end. It would be interesting in this connexion to know more of the relation of egg and embryo to the pouch and to the corpora lutea in Echidna. In Ornithorhynchus the eggs are hatched in a nest and there is no pouch.
"If any unknown individual," observed Macallan, "and not Captain Cook, had reported the existence of such an animal as the ornithorhynchus, or duck-billed platypus, without bringing home the specimen as a proof; who would have credited his statement?"
"I didn't mean an altogether animal, or even a bird, but any a a a ." She seemed puzzled how to speak of the Platypus, when the strange creature, seeing the well-meaning embarrassment of the Kangaroo, said affably, "any mammal or Ornithorhynchus Paradoxus." "Exactly," said the Kangaroo, brightening up, although she hadn't the least idea what a mammal was.
Even so, though Australia is still zoologically in the secondary period, it is a secondary period a good deal altered and adapted in detail to meet the wants of special situations. The oldest types of animals in Australia are the ornithorhynchus and the echidna, the 'beast with a bill, and the 'porcupine ant-eater' of popular natural history.
Altogether it was such a funny object that she was inclined to laugh, only the Kangaroo looked so serious, that she tried to look serious too, as if there was nothing strange in the appearance of the Platypus. "I am the Ornithorhynchus Paradoxus!" said the Platypus pompously. "I am Dot," said the little girl. "Now we know one another's names," said the Platypus, with satisfaction.
Altogether it was such a funny object that she was inclined to laugh, only the Kangaroo looked so serious, that she tried to look serious too, as if there was nothing strange in the appearance of the Platypus. "I am the Ornithorhynchus Paradoxus!" said the Platypus pompously. "I am Dot," said the little girl. "Now we know one another's names," said the Platypus, with satisfaction.
In her zeal not to be dubbed such a title for the rest of the day as a jibbering ornithorhynchus, Betty urged Lad along until she nearly bounced out of her saddle, and the letter lay on the hall table, forgotten by both the girls who had promised to post it.
Upon these the Ornithorhynchus voyaged in peace; voyaged from clime to clime, from hemisphere to hemisphere, in contentment and comfort, in virile interest in the constant change of scene, in humble thankfulness for its privileges, in ever-increasing enthusiasm in the development of the great theory upon whose validity it had staked its life, its fortunes, and its sacred honor, if I may use such expressions without impropriety in connection with an episode of this nature.
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