CONTEMPORARY OPINIONS. 41 



used to be considered as the parents of the permanent 

 teeth ; whereas Goodsir showed that they are both laid 

 down separately and independently of each other. The 

 profession fully agree as to the value of Goodsir s disco- 

 very. Mr. Flower, one of the latest authorities on this 

 subject, appropriately says — " It should be remembered 

 that instead of there being any such relation between 

 the permanent and milk-teeth as that expressed by the 

 terms 'progeny' and 'parent' sometimes applied to 

 them, they are both formed side by side from inde- 

 pendent portions of the primitive dental groove, and 

 may rather be compared to twin brothers; one of 

 which, destined for early functional activity, proceeds 

 rapidly in its development, while the other makes little 

 progress until the time approaches when it is called 

 upon to take the place of its more precocious locum 

 te nens." — (Trans. Roy. Soc. London, 1867.) 



From Vesalius to our own times, the milk teeth 

 used to be looked upon as the germs of the permanent 

 ones. Eustachius was almost the exceptional instance 

 to the current opinion ; he believed that the germs of 

 both sets of teeth existed in the jaw of the embryo. 

 Duverney and Herissant had a glimpse of the nature 

 of the follicles and their relation to the gums, and 

 .Joiml.iin gave a minute description of the follicle from 

 its first appearance in the fcetal jaw till the period of 

 birth. lUandin considered the teeth as productions of 

 the mucous membrane analogous to the nails and hair, 

 and seems to have approximated more closely to the 

 true conception of the dental follicle thai) any of his 



