Primitive animals / by Geoffrey Smith.

  • Smith, Geoffrey, 1881-1916.
Date:
1911
Catalogue details

Licence: In copyright

Credit: Primitive animals / by Geoffrey Smith. Source: Wellcome Collection.

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    undeveloped state while they are still exceedingly small; thus the newly born young of a kangaroo, which when adult measures upward of six feet high, is less than half-an-inch in length when first delivered by the mother, and it is still in the developmental stage of a very early foetus of one of the higher Mammals. After delivery, the mother picks up the tiny foetus with her lips and transfers it to her pouch, placing the lips of the foetus on to one of the nipples which are enclosed in the pouch. The lips of the foetus become firmly fixed to the nipple, and here it is suckled by the mother for a very long period until it is about a quarter full grown. The discovery of the minute foetus attached to the nipple of the mother led to the idea, which is still current among the settlers in Australia, that the young are actually born in this situation, a supposition so grotesquely at variance with all the facts of Mammalian anatomy and physiology as hardly to deserve the minute and circumstantial refutation it has naturally received. The birth of the Marsupial young in so small, helpless and undeveloped a condition, as compared with the young of an ordinary Mammal, is due to the comparatively inferior nutrition of the embryo while still in the uterus of the mother. The Mar- supial embryo is in fact half-way between the condition of the Monotreme, where the embryo is delivered as an egg and is entirely dependent on