THE HAMILTON ASSOCIATION. 67 



species of serpents, have beneath their scaly coats two elementary 

 extremities, rudiments of the organs of locomotion, just anterior to 

 the base of the tail, and in which are found a series of bones repre- 

 senting those of the hind limbs of Mammals. These rudiments, 

 though imperfectly developed, are yet acted upon by powerful 

 muscles, and thus become a strong fulcrum in the animals' move- 

 ments or in seizing their prey. We may pass from lizards to serpents 

 through a continuous series of forms in which the limbs become 

 more and more feeble, until all external traces of them are lost. 

 Such, for instance, are the family of Chalcidae, one of which, the 

 Pseudopus, found in Northern Africa and Greece, has only the rudi^, 

 ments of hind limbs ; whilst another, the ChiroteSj a native of 

 Mexico, has only the fore limbs, placed a short distance behind the 

 head, yet so developed in its case as to be used. In the family of 

 Scincidae, the Evesia, a native of India, has the limbs reduced to 

 footless appendages. In the common slow worm or blind worm, 

 rudimentary limbs are found beneath the skin on dissection. 



In a species of Turtle, the Matamata, found in Guiana, rudi- 

 mentary ears or ear-like membraneous prolongations of skin on 

 the head exist. Again, at the inner corner of the human eye is a 

 third eyelid, known, I have no doubt, to very few persons, and an 

 object of attention only to anatomists. In other animals, birds 

 especially, it is of full size and of great utility, enabling them to turn 

 their eyes upwards to the sun, a feat they could never accomplish 

 were not the visual organ thus protected. 



A curious animal has been discovered in the Amazon, called 

 the Lepidosiren, with the scales and mucous covering of a fish, but 

 with rudimentary limbs, represented by four tentacular appendages, 

 not jointed. Another species is met with in South Africa, with the 

 tentaculae jointed. 



Professor Owen, speaking of rudimentary forms, thinks that we 

 have not in this globe all the diversities of which a general pattern 

 or archetype is susceptible, and that limbs which are found only in 

 an undeveloped state in this world, may be fully developed in the 

 other planetary bodies. Arguing on this principle, Dr. Leitch, in 

 his work. " God's Glory in the Heavens," says there are undeveloped 

 volcanic structures on the face of the earth, similar ones to which 

 have long ago been fully developed in the moon, and by analogy he 



