66 JOURNAL AND PROCEEDINGS 



rated by as wide an interval as the lichen from the palm tree. But 

 the secret once fathomed and the type established, their visible con- 

 nection is read off plain. Owen has satisfactorily demonstrated that 

 by changes of one form alone, the archetypal vertebra, all varieties 

 have been effected, yet all are connected. Some idea of the infinity 

 of life may be formed by a comparsion between the microscopic 

 animal, which,, when magnified 5,000 times, only appears the size of 

 a visible point, and the huge form of the whale, measuring some- 

 thing like 100 feet ; yet all the intermediate space is filled up with 

 animated beings of every form and order, more or less connected ; 

 or in the vegetable kingdom by comparing the microscopic mildew 

 with the giant trees of California, and yet knowing that the immense 

 interval is filled with plants, shrubs and trees of every form and size. 

 One mark of the connecting link of animal life exists in what are 

 known amongst naturalists as rudimentary structures. There is dis- 

 coverable in all vertebrate animals a general type amidst the diversity 

 of form ; there are undeveloped limbs or members which are of no 

 use to the particular animals in which they are found. Apparently 

 functionless and useless where they occur, but representing similar 

 parts of large size and functional importance in other animals, they 

 seem to serve no other purpose than to prevent the gaps in the scale 

 of nature being too large. As examples of these rudimentary 

 structures, I will mention a few : The Rorqual, a species of whale 

 has rounded horny filaments in its jaws, united by a common mem- 

 brane, in addition to the balaena or whalebone, these filaments ap- 

 parently corresponding to the teeth of the spermaceti whale. The 

 foetal teeth of the common whale, and of the front part of the jaw of 

 ruminating animals, are minute in size and never cut the gum, but 

 are absorbed without ever coming into use, and no other teeth 

 succeed them or represent them in the adult condition of those 

 animals. The Ornithorhyncus of Australia possessing no teeth, has 

 a horny appendage on each side of either mandible, but without 

 roots, evidently corresponding to teeth in other animals. The 

 Apteryx, a New Zealand bird, utterly incapable of flight, has an 

 almost imperceptible wing in quite a rudimentary condition, yet it 

 contains bones which are miniature representatives of the ordinary 

 wingbones of birds of flight. In the Emu the wings are discernible, 

 and in the Ostrich they become largely developed, although useless 

 as wings proper. The Anacondas and Boas, the largest known 



